why not take?


I wouldn't worry about it. The thing to realize is that all moves are completely lost for Black. The move 18... e5 may just be slightly less completely losing because it gives room for the bishop to develop.
Lol so the machine... Doesn't know all?
Computers are able to see moves ahead of us most of the time, save for some things like fortresses.
After 18. Rd1, White is severely lacking in material. One bishop, one knight and two pawns down. The reason why the computer might suggest 18...e5 is that this move opens up a path for Black's bishop on f8 and some room around the king. Since Black is already so much ahead in material, giving one pawn back to White to gain quick activity is quite a good measure for Black.
Other moves work quite well too, but not your played move 18...g6? with a mate in two for White after 19. Qxc8+ Bxc8 20. Rd8#.
As Black, I realised that I would have personally played the sub-optimal 18...Rxc7? which would cause Black's advantage to evaporate almost fully.
I wouldn't worry about it. The thing to realize is that all moves are completely lost for Black. The move 18... e5 may just be slightly less completely losing because it gives room for the bishop to develop.
Black is completely winning at that point, but has immediate pitfalls to avoid.

Oh wow very interesting though I feel I should have seen this perhaps less fulfilment of the states pro cannabis law and more board time lol. It needs more cowbell! I thank both of you. However again I must ask tho how did you post those lo lovely (png?) 8m using the app, is it via browser? And also... Sooo again what's preventing whites Bishop from just taking my E5 pawn on turn 19 if I did that? Just the fact that it'll allow me to have a turn or 2 more of breathing room?
Oh wow very interesting though I feel I should have seen this perhaps less fulfilment of the states pro cannabis law and more board time lol. It needs more cowbell! I thank both of you. However again I must ask tho how did you post those lo lovely (png?) 8m using the app, is it via browser? And also... Sooo again what's preventing whites Bishop from just taking my E5 pawn on turn 19 if I did that? Just the fact that it'll allow me to have a turn or 2 more of breathing room?
I used the browser.
After 18...e5! White is more than welcome to play 19.Bxe5. Black will be able to bring his last remaining piece strongly into play with Bc5, which will also allow him to castle. At that point, Black will have a strong attack and overwhelming material superiority. What's a pawn compared to all that? When you're way up in material, a pawn is nothing compared to mobilizing your extra pieces