How bad is not having Metal Support for BigSur/Monterrey/Ventura?

I'm still working on trying to figure out which one to upgrade my older Macs to.

I have the following:
Late 2009 iMac (11,1) 27" with ATI Radeon 4850 (So there is no metal Support)
Mid 2012 MacBook Air 11" (I believe this has Metal support so it should be ok)

I have been looking into possibly upgrading the GPU in the iMac, but 1: I"m still trying to figure out if I can, because I'm reading 2 different things saying that this model isn't socketed, but then seeing that people can and 2: If I can go from ATI/AMD to NVIDIA. But either way right now the process is a bit cost prohibitive as even looking for the compatible cards, seem to all be in the $200 range still which is a bit more than I'm willing to spend on a legacy machine.

I think that the only major thing that I might possibly need metal support for is Zoom (but I think there are workarounds for this) and the occasional FindMy and Maps.

Author: @cewong2