As someone who briefly lived a similar dream, I wish someone had pointed out to me that you're still going to have to get your old bones up to get the wired controllers for those older consoles. I'd just keep the old school composite switch accessible so you can plug in whatever you want to play while you're grabbing the controllers and plugging in the cartridge. Then you just need an HDMI switcher, which could also be your surroud sound system (if you're spending money anyway...)

probably just a switcher for each connector type: coax, rca, hdmi, etc.

haha heck this is where being in the "biz" has its advantages. (home AV)

look into something like a b&k ct600 kit. whichever is the composite/component video Switcher piece.

key digital makes some stuff.

eBay!

Input switcher things still exist specifically for this kinda stuff but they are getting harder to find. Especially ones with inputs as old as the NES using the RF/antenna hook thingy.

Older top end home receivers have a lot of video and hdmi inputs. I've been rescuing them from the garbage. If it had a composite input on it most people don't want it.

Most of the really old game systems make you put a cartridge in them anyway, not sure how you'd get over that.

I found this really cool modular switch, but they seem to always be out of stock:

https://scalablevideoswitch.com/

I hate to be that guy, but it may be worth weighing your options with an emulation setup. That way you can okay everything on one machine, on one tv input, and not need to get up to turn anything on.

If you like the original controllers 8bitdo sells conversion kits that make old controllers wireless. It's an investment for sure, but idk, might be your cup of tea.

More TVs, obviously.

EDIT: You could probably use an HDMI Matrix for your HDMI needs. Don't know about component/composite needs though.

I had a pcie analogue camera capture card for CCTV applications, took 8x composite on a pigtail out the back

Con: need a PC

Something I just thought of that I didn't before is powering the consoles on and off. You might be able to get a power strip with a wireless connection to remotely turn off individual outlets. Then you set each console to the on position and turn them off by turning off the outlet.

Not sure what the consequences on the hardware level would be, but essentially unplugging it from the wall while it is powered on doesn't usually harm a game console any different than just powering it off with the switch would. Maybe on the newer stuff, or the original Xbox maybe, since theyre more similar to PCs. But older stuff I can't see that being a problem.

If you wanted a truly remote setup, that is.

Wireless controllers hanging on the wall with receivers already plugged into the consoles, app controlled power outlets, remote for TV, and remote for input matrices. Might be able to consolidate with a control system or IR based solution to reduce to 1 remote for TV and input matrices. Flaschcart or modded consoles loaded with all the games already. Etc.