Hello,
You actually can give your opponents more time on chess.com!
This only works in direct friend games, and not randomly matched ones, and it only works on the website to my knowledge. But, while on the website, you'll see a button that adds time to your opponent's clock. Every time you press it, your opponent will gain 15 seconds.
This option can only be used in friend games and not random ones, but you can do this even in rated friend games, and the game will not become unrated no matter how much time you add.
I hope this helps!
I hate seeing my opponent run out of time or resign because they are running low on time when there is an interesting position, and especially when I know I have a huge advantage but don't clearly see the win. I'll give an example.
I have a common problem with positions like this one.
FEN: 1k1r4/2pb3p/Qpp3p1/4r3/P7/7P/1P3PP1/R5K1 w - - 0 25
I had the advantage, but I also had a lot more time on the clock. I chose a5 instead of b4, and b4 wasn't even the best move. After the rooks traded, I had about 5 more minutes on the clock. And they just let the time run out. I can't complain about them, because it is clear I can win on time. If I gave them more time on the clock, they would probably have continued playing and it would be a good training experience for me.
I'll focus the position at move 25 for white.