Although my R5 has never frozen it is not like a DSLR in focusing. It has other AF capabilities though like focusing at very low light and IBIS is very good when combined with IS capable RF lenses (and probably EF but I have not tested them). But even so I very much prefer it to my R which I have sold it (and I did not regret it).
I just do not trust R5 to catch some BIF or unique birding moments like I trust my Nikon and Canon DSLRs.
5DsR is a very nice camera if you expose correctly. These days it I believe it can be found at very good price.
Having said that I believe having or not a R5 depends:
1. On what you shoot most.
2. If you have many good EF lenses.
3. A future R5 firmware
The freeze mentioned above cannot be R5's fault but SD card's fault. I remember my first and only freeze in 5DMkIV has been due to an SD card. I removed it and 5DIV recovered. Interesting this card had some issues in other but not all my DSLRs!!! After some full formats in a card reader and low level formats it must have recovered - or I have put it in some other camera - because I never had an issue again.
Well, well, well...
Sooner or later I'll certainly buy an R5 II or an R1.
Or, as you suggest, wait for a reliable firmware.
The trouble, in my case, is that:
-I own 14 EF lenses i'm fully satisfied with
-I love the 5 DIV
-I shoot mostly landscapes and macro, so AF matters less
-I had high expectations of the RF 100 macro, wanted to buy it with R3 or R5, no comment...
-I (stupidly?) expect a new camera to be as reliable as a Nikon F2, Leicaflex or an EOS 5 DII or 5 DIII
But still believe Canon can fix it!