Why is the window so slow? And how can I fix it?

Question

I am making a simple pi camera app using pygame. But for some reason the preview window is running terribly. Can someone help me fix this. It looks terrible like this. There must be a better way of achieving this. Code is shown below:

import os
import sys
from click import command
import pygame
from datetime import datetime
import picamera
from io import BytesIO
from subprocess import call

pygame.init()

width = 1280
height = 720

screen = pygame.display.set_mode((width,height), 0)

isRec = True
menu = 0
camera = picamera.PiCamera()
camera.resolution = (width, height)

def drawMainBtns():
    camImg = pygame.image.load('res/cam.png')
    vcamImg = pygame.image.load('res/vcam.png')
    galImg = pygame.image.load('res/gal.png')

    camImg = pygame.transform.scale(camImg, (138,105))
    screen.blit(camImg, (40,40))

    vcamImg = pygame.transform.scale(vcamImg, (138,105))
    screen.blit(vcamImg, (215,40))

    galImg = pygame.transform.scale(galImg, (138,105))
    screen.blit(galImg, (width - 138 - 40,height - 105 - 40))

def gallery():
    print('Opened gallery')
    screen.fill((255,255,255))

while True:
    if menu == 0:
        stream = BytesIO()
        camera.capture(stream, use_video_port=True, format='rgb')
        stream.seek(0)

        image1 = pygame.image.frombuffer(stream.read(), (width,height), 'RGB')
        image1 = pygame.transform.scale(image1,(width,height))
        screen.blit(image1,(0,0))

        drawMainBtns()

    pygame.display.update()

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
        elif event.type == pygame.MOUSEBUTTONDOWN:
            print(pygame.mouse.get_pos())
            x, y = pygame.mouse.get_pos()

            if menu == 0:
                if x > 40 and x < 180:
                    if y > 40 and y < 160:
                        now = datetime.now()
                        t_string = now.strftime("%d-%m-%Y_%H-%M-%S")
                        camera.capture('pics/' + t_string + '.jpg')
                        print("Cheese!")

                if x > 215 and x < 360:
                    if y > 40 and y < 150:
                        if isRec:
                            isRec = False
                            print('Started recording')
                            camera.start_recording('tmp/0.h264')
                        else:
                            isRec = True
                            print('Stopped recording')
                            camera.stop_recording()

                            now = datetime.now()
                            t_string = now.strftime("%d-%m-%Y_%H-%M-%S")
                            command = 'MP4Box -add tmp/0.h264 vids/' + t_string + '.mp4'
                            call(command, shell=True)

                            os.remove('tmp/0.h264')
            
                if x > 1095 and x < 1230:
                    if y > 576 and y < 680:
                        menu = 1
                        gallery()
                    

Please help me with this. This is incredibly important to me. I'm running a pi4.

EDIT I have optimized it a bit more so now pygame is running fin at normal speeds. picamera is taking up all of the resources.