Not sure about all the reasons you used. But when I call a plumber in my town, the good ones I have used before or similar, they can't get to me within 48-72 hours. Those guys are really busy. Not that I have a plumbing issues at my offices - I just listed my house to move into a bigger home, and there was a small shower leak in the master bathroom, thanks to my wife's long hair - the shower drains can clog horribly if unchecked for sometime. But back to the plumbers, give your local plumbers a call if you live in a medium sized city, those guys are doing well for themselves.
If housing market is doing well, then painters are doing well. All those new homes or homes that are about to be listed need painters. New businesses opening shops need painters. Heck, seasonal home improvements need painters. Look at how many Sherwin-Williams Paint shops are opening up around the country, someone has to help many of those customers paint their homes. Yes, commercials on TV make us think we can do it ourselves... but that's if you know what you are doing. So check, painters is a good gig too.
Locksmiths, those are hit and miss. But they are in the opportunist markets (emergencies), just like tow-trucks.
Franchisees are all about location, location, location. That's it. The rest will fall in place.
With the advent of technology like Zillow (read the Zillow book), realtors work have evolved from what use to be 90-120 days process to matter of days to sell a property. My younger brother sold his condo, and he closed in 10 days. 20 years or so ago, before cell phones and emails, buyer realtors use to run down to the local county office to look up property owner documents and confirm tons of information in person over 2-5 days process, then run to a phone booth, call the seller's agent about an offer, wait couple of weeks for a response, mail in a contract (2-3 days), have an attorney review it (a week), attorney then mails the buyer (another week), then buyer mails back to buyer agent, and so on. Could you imagine if that happened today? Now all is done in matter of hours; emails (group emails), e-sign documents, county auditor'a have everything online, closing can be done remotely too. So realtors saved so much time, as a result their income went up quite a bit. The profession is still evolving and has a good prospect and income.