Ages ago, it was common in mountainous terrain to find remote base stations on 146.94, and later 146.52, when that became the simplex calling channel. These remote bases were usually linked to a UHF repeater. Most of those were private repeaters, so, the user was effectively using a remote mountaintop radio to work 146.52. Note that under the rules, any amateur station can be remotely operated. It makes no difference if it's via radio. leased phone line like we used to do, or the Internet as so many do today.
I've long thought that we could use a system similar to the old 'LiTZ' system - or 'long tone zero', where you would get on a common frequency and use a touchtone pad to send a 1 second long 'zero' to activate a link to an active local repeater.
Today, pretty much everyone has PL capability, so just designating a common PL tone and simplex frequency would do the job.
Yes, there would be a definite benefit if such a system could be adopted on a wide-ranging basis.
Another thought I've had along those lines would be an increase in a common APRS feature. On some APRS rigs, if you receive a particularly coded information packet, with the frequency info for a local repeater, there is a button that will automatically QSY you to that frequency. This is very useful for visitors.