There’s several problems here:

Giving homeless people food you cannot serve due to it being under heat lamps too long isn’t cool. If it’s risky for you it’s riskier for them as they don’t have their own space to be sick in. This is why many hot dishes are thrown out.

Homeless shelters and food assistance programs discourage giving old food as it sends the message to recipients that they aren’t worth getting a fresh meal. It’s about decency.

My mom ran an interim housing program, a food bank, and a homeless shelter. When restaurants gave food they made it for the shelter. It wasn’t their leftovers. The only things that were “old” were the Starbuck’s pastries as they drove them over twice a day and thus the guys at the shelter weren’t getting stale stuff.