For you who use barebones services maybe not but I noticed that by default LTSC 2021 (21H2) has more services running by default and more dependencies for features. For example, screen brightness control on latops and night light need more services running in the background than LTSC 2019 (1809).not a lot between the two to be honest at first glance.
unfortunately even for old hardware Win10/11 is almost mandatory.
Realteks audio drivers/software are massive so i prefer a usb audio interface.almost. can you strike lucky with sound cards/usb audio devices which is my thing.