I've added a few smart devices to the house and I'm trying to find something that may or may not exist but my Google-fu appears weak on this case...

I have added smart switches to all my exterior lighting and can set them up on various schedules, turn them on/off from my phone, etc at this point.  I can now turn on all exterior lights by grouping those switches into a single virtual switch and toggle them all on/off via one button on my phone app.  I'd like to install a wallplate switch to serve that same function without the phone.  Doable or did i just give someone a million$ idea?

What brand switches did you use?

I am not a smart home guy, but I have a couple thoughts on potential ways to accomplish this:

Use a smart button as your switch for all exterior lights.

Use an IFTTT routine to make one smart switch turn on all of the smart switches. Make it the smart switch for one of the exterior lights that you would most likely want all exterior lights to turn on with.

Use a smart home assistant and make a voice routine to turn on all exterior lights and switch all of the smart switches on.

Smart Life switches

https://www.amazon.com/Treatlife-Smart-Light-Switch-Assistant/dp/B07R4MFWCQ

Easy to install, look nice,  and work well.

"Smart button" is exactly what I was looking for... I'd never heard that term before - thanks!

I’m not sure how to accomplish it with the switches you have. Some manufacturers or technologies allow for a switch to trigger a macro or control a group but most would interact with some sort of hub. From what little reading I did on what you have a smart button mentioned above may be your best option.