Best if price doesn't matter iPhone 11 Pro. To me the size is negligible, and it's the most complete package all round.
Android side of things, unless camera photo quality and having stock Android is super important to you, S10e. It's way cheaper too.
I have both the S10e and Pixel 4 with me now and I use the S10e most of the time. Nicer screen quality with better brightness, better battery life, more features (3.5mm jack, wireless charging, wide angle cam). I consider capacitive fingerprint sensor a plus point too since the banking apps I use don't support Pixel 4 face unlock, so extra hassle.
Which is best small form factor phone??