Which router to replace 2011 Apple Time Capsule

I am using the Time Capsule with two AEX WiFi extenders for WiFi needs at home that also serves Dots around the home. Sonos is served via Sonos net, with a Boost and a WD My Cloud NAS wired to the LAN ports of the Time Capsule. This is all working fine, but I may have the opportunity to manage the logistics of replacement and one never knows how much life is left in the 2011 TC.
My question is what would be a good modern replacement for the Time Capsule with the following conditions:
1. International voltage range like Sonos kit.
2. Should be available in Best Buy stores in the US.
3. Should work as a drop in replacement for Sonos.
4. Should work as a drop in replacement for WiFi - either with the two AEX extenders at either end of a single floor apartment, or by not needing these.
5. If 4 is not likely, what extenders will have to be bought as well?

While I use the Time Capsule for Time Machine back ups, I can easily use a wired to Mac HDD to do this, so this functionality is not needed.

Airport Extreme would have been the obvious choice but for the concern that Apple have stopped development of the line since 2016.

Thank you!