x470 stuck after bios update

I think you did not get me!!
I am talking about the Power ON Switch on the cabinet.
Turn off the PSU, remove the PSU power cord from mains supply and now long press the PowerON button on cabinet and hold it there for at least 30 seconds. This will clear any static charges on the board and overall system just in case that's responsible for this behavior.

I am not taking about battery out. Battery out will reset the BIOS which you have already tried and did not work I guess.
All the best.
That's it from my side!

In absence of flashback BIOS update option, for some reasons it seems the board is almost bricked. Did you try the 30 second long press and hold power button on cabinet when mains supply to PSU if off?
If that did not work, you may want to re-seat all discrete parts and check again

else take it to a repair center. Don't say anything about BIOS update, just tell them that the system is now stuck at boot logo.

That one is ancient and it was a bridge bios from 1.90 to higher.
Your bios 3.60 is already higher than 2.20.
So you should always go for a higher one instead of flashing back to that 2.20 as depending on your CPU might not start up again.

Go for one of the 4.70 or 5.10 before flashing to one of the 10.x ones.

Also pls. note BIOS also depends on CPU and GPU used.
If the MoBo is the X470 Taichi I would suggest to try flashin with 5.10

Sometimes the BIOS update page on the vendor support site says that after an x version, before you go to z there's y in between that must be first flashed before jumping to z.

e.g. you are say on v4.1 and the latest is v8.2 but there's a Bridge v5.1 in between that must be flashed before you go straight to 8.2

But without knowing the exact board model, i can't comment if there was any Bridge bios applicable. You need to check the support section for your specific model on ASRock site.

The long press power button when mains is Off sometimes clears any static on the board that is preventing boot. Not too sure if you tried that.