How to make pygame collidepoint function work with my game

Question

I am working on my very first game project on python using pygame. It is supposed to be shoot em up like game.

Currently i add bullets and mobs to their respective lists to be able to handle each bullet and each mob separately (copied this from another project online, not sure if it is the best way).

I try to use collidepoint function to check if bullets coordinates are in mobs rectangle but the actions defined after the check never applies.

import pygame
from random import choice

class Mob(object):
    def __init__(self):
        self.image = pygame.image.load("hirvio.png")
        self.rect = self.image.get_rect()
        self.x = choice(range(50, 590))
        self.y = -50
# another idea for hibox before trying the collidepoint function
#        self.hitbox = (self.x, self.y, self.image.get_width(), self.image.get_height())

    def collide_check(self, x, y):
        self.collide = self.rect.collidepoint(x, y)
        if self.collide:
            return True

    def create(self):
        screen.blit(self.image, (self.x, self.y))
        self.move()
    
    def move(self):
        self.y += 3
    
    def hit(self):
        score.add()

class Bullet(object):
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def draw(self, screen):
        pygame.draw.circle(screen, (0, 255, 0), (self.x, self.y), 3)
        self.move()
    
    def move(self):
        self.y -= 5

    def call(self):
        return (self.x, self.y)
            
class Player:
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("robo.png")
        self.rect = self.image.get_rect()
        self.x = 320
        self.y = 860

        self.left = False
        self.right = False
        self.up = False
        self.down = False

    def fire(self):
        bullets.append(Bullet((self.x + self.image.get_width()/2), self.y))

class Score(object):
    def __init__(self):
        self.score = 3
        self.font = pygame.font.SysFont("Arial", 24)
        self.score_text = self.font.render(str(self.score), True, (255, 0, 0))

    def update(self):
        self.score_text = self.font.render(str(self.score), True, (255, 0, 0))

    def draw(self):
        screen.blit(self.score_text, (590, 50))

    def add(self):
        self.score += 1

def main():
    pygame.init()
    global screen
    screen = pygame.display.set_mode((640, 960))
    pygame.display.set_caption("Robo Shooter")

    screen.fill((0, 0, 0))

    global player
    player = Player()

    global bullets
    bullets = []

    global mobs
    mobs = []

    global score
    score = Score()

    clock = pygame.time.Clock()

    while True:
        clock.tick(60)
        check_events()
        flip_display(screen)

def check_events():    
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            exit()
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                player.left = True
            if event.key == pygame.K_RIGHT:
                player.right = True
            if event.key == pygame.K_UP:
                player.up = True
            if event.key == pygame.K_DOWN:
                player.down = True
            if event.key == pygame.K_SPACE:
                player.fire()
            if event.key == pygame.K_q:
                mobs.append(Mob())
        elif event.type == pygame.KEYUP:
            if event.key == pygame.K_LEFT:
                player.left = False
            if event.key == pygame.K_RIGHT:
                player.right = False
            if event.key == pygame.K_UP:
                player.up = False
            if event.key == pygame.K_DOWN:
                player.down = False
    if player.left:
        if player.x > 0:
            player.x -= 4
    if player.right:
        if player.x < 640 - player.image.get_width():
            player.x += 4
    if player.up:
        if player.y > 0:
            player.y -= 4
    if player.down:
        if player.y < 960 - player.image.get_height():
            player.y += 4

    for bullet in bullets:
        for mob in mobs:
#            collide = mob.rect.collidepoint(bullet.x, bullet.y)
            if mob.collide_check(bullet.x, bullet.y):
                bullets.pop(bullets.index(bullet))
                score.add()
# another idea for hitbox
#        if bullet.y < mob.hitbox[1] + mob.hitbox[3] and bullet.y > mob.hitbox[1]:
#            if bullet.x > mob.hitbox[0] and bullet.x < mob.hitbox[0] + mob.hitbox[2]:
        if bullet.y < 0:
            bullets.pop(bullets.index(bullet))
    
    for mob in mobs:
        if mob.y > 1000:
            mobs.pop(mobs.index(mob))

    score.update()

def flip_display(screen):
    screen.fill((10, 10, 10))
    screen.blit(player.image, (player.x, player.y))
    for bullet in bullets:
        bullet.draw(screen)
    for mob in mobs:
        mob.create()
    score.draw()
    pygame.display.flip()

if __name__ == "__main__":
    main()

I'd assume the problem is either some kind of syntax problem since i'm very new to python still or then maybe related to the lists of bullets and mobs. But mostly I just don't understand why collidepoint does not work...