Okay, if what you say is correct, I only ask the Big Sur is released to 2012 and later until iMac with Apple Silicon iMacs are available??
what is so wrong with that?
PS. My iMac is running so well!
I have moved all my data onto the cloud ☁️
I have a clean iMac (use a software cleaner)
uninstall Apps you don’t use.
I have a very quick iMac on a very high speed Fibre line.
so why Big Sur?
the inter-relationship with all my iPhones, iPads and exposure/training with Big Sur until iMac Apple Silicon is out: then I’ll “jump ship” to my next iMac 27...29 inch BUT, I’ll still use and have my late 2013 27 inch iMac 🖥 then I’ll upgrade it to an SSD drive...