That phone is just going to keep getting slower. Not sure which combination of internal storage/RAM you got, but the processor that Samsung uses in that is bottom of the barrel. One of the reviews I read mentioned "It's there to just keep the lights on".
The cameras, as hardware items, are going to be fine. The issue your phone has, will continue to have, and which will continue to get worse is that processor is just not built to handle much more than playing Wordle, streaming videos over Wifi, and doing 'phone things'.
Even if a third party device existed, it would suffer the same issues - the processor is going to be pretty maxed out while taking pictures and video.
You could possibly look into third party camera apps - those usually come pretty highly recommended for any phone that's not a Pixel/iPhone, although I don't have any good recommendations. You can also alleviate some of the strain by changing the resolution of your pictures to a lower setting, and turning HDR off (if that's a feature included in your camera software).
Otherwise, it might be enough of a reason to upgrade to a slightly more expensive phone. You can find some great used phones <$200 on Swappa, or you can buy a 1-2 year old higher tier phone.