Using Classic Outlook on Windows for personal email, calendar, and contact management
I was looking for a solution to this myself today. Going down the rabbit hole starting here, I came across this link that someone else posted... I don't even remember how I got there, but here's your workaround. It's so easy and you don't have to download 3rd party software or go reverting to an old version of Outlook or changing registry keys. You literally just add the button to your ribbon and/or quick access toolbar.
The only downside is that if the original meeting organizer sends an update and you accept it (I'm assuming you have to accept it for this to happen) then you'll lose any edits you made yourself. So just keep that in mind!
I work for a state university and our IT department forces new versions and updates on us, so I can confirm this works at least with what I have: Outlook for Microsoft 365 MSO (Version 2402 Build 16.0.17328.20550) 64-bit.
Note: I am NOT using the "new Outlook" because when I tried it I lost other functionality that I required (adding a shared mailbox as a separate account vs it being added within my account as if it was just another folder - this prevents adding any of those folders as favorites, which I MUST be able to do).