They don’t all have the opportunity to surrender unfortunately, that’s a very childish attempt to make complicated issues black and white.
It’s a lot harder than you are trying to portray it to abandon your unit on your own and just walk up to 5, 10 miles to the Ukrainians. Firstly they’re very heavily bombarded with propaganda that the Ukrainians won’t accept surrender because of the awful things Russians have done. Then, If you get caught leaving you will be shot, if you don’t surrender properly you will be shot, if someone doesn’t realise you’re surrendering, you’ll be shot. In fact there’s a nonzero chance you’ll get shot even if you do everything right.
It’s a nice and easy throwaway platitude to say everyone can surrender but it’s childish and not how wars actually work.
Plenty of them are surrendering because of how many are there against their will, but try not to reduce everything to childish levels so you can celebrate watching a seemingly unarmed man get shot 100 times while running away and bleed to death in someone’s garden.