lol, no... just no.
@OP - Don't own any franchises nor have looked into any. But I know quite a few people who own franchises.
I live in a market of around 100,000 people and know the guy who owns all the Tim Hortons (seven or eight) and the guy who owns all the Wendy's (two with a third opening this fall).
Also know the guy who owns two Tim Hortons in the military base / military town (largest in Canada) just a few minutes away from the city. Also have talked briefly with the guy who owns all the Tim Hortons (not sure if he has the rights to Wendy's too, usually they're packaged here so you have a duplex of Tims/Wendys) in the whole province of P.E.I but know one of his good friends.
So don't know too much first hand knowledge, but neither does anybody in this thread so.
First of all what people forget is you have a few different franchise models, the most popular is where you get the rights to an area. Part of the deal may include an understanding or an actual contract to build more stores in the future based on the success of the first (one this year, one next year, one within the following five years, etc).
Second when opening a franchise you'll be given an estimated revenue/profit based on the company's evaluation of the market, etc. I know of many people who know that a Tim Hortons can do well in a small town and are willing and more than able to pay up for it but Tim Hortons refuses based on it's core criteria that has to be hit. So even if you have your own data, and ultimately it is your own money, Tim's is very strict about where it's stores are put.
I believe Subway's estimated profits are around 50k (average) for the owner so using that as a parameter to determine if franchises are worth going after is ridiculous.
I know for a fact that the Wendy's guy does 2-3 million a year (since we're quite good friends). Tim Horton's locally here do 4-5 million as told to me by the Wendy's guy (they're friends). Tim's guy in the military base/area probably (guesstimating) does 1.5 million or so.
The guy who owns all the ones on P.E.I apparently does well into the eight figures a year. He lives in what looks like a legitimate castle and loves horses so has a staff to take care of his daughters horses that all cost more than Ferraris.
None of them work overly hard. Rules may have changed since they bought their respective rights but I know the owner of Tim's locally doesn't ever go to the stores unless needed and I think the Wendy's guy goes in every now and then just when he's bored (no kids, no wife and no other hobby/income).
So definitely a lot of money to be made in quite small markets. The thing though at this point all the rights to most of these franchises are already taken up. And I'm not sure if they can be sold except back to the company.
On the flip side though a family friend bought the franchise for Home Hardware Home (Canadian franchise I believe) which was basically a shitty Ikea. He poured everything he had into it, had a building built instead of renting, and worked 15 hours a day for a year and just last month he filed bankruptcy and closed shop. He never had a profitable week except for his liquidation week before he closed shop.
So there you have it. In my limited experience of just talking to friends who own franchises (namely the Wendy's guy) and gossiping about others in the industry, how much they make, what they drive, where they live, etc. that's my perspective. Probably a pretty accurate one.
It's certainly a lot of work. You need to get your clearance from the city to build, find the right location (so crucial), train your initial staff, probably be at the store all day for at least a month or so, have your store built to specific specifications that the company will give you, etc. It's great when it gets to the passive stage, but I think everybody would tell you it's initially a load of work.
But ultimately all these guys live in million dollar homes, each have at least one exotic (200k+) car, spend at least a quarter or two outside the country not working, play an unimaginable amount of golf, etc.
Also fun fact: I guess most guys with multiple stores have like a "general manager" for all your stores that's essentially what you should be doing as a franchise owner. They just drive to every store and stay for a few hours a day making sure everything is going alright, hiring, firing, basic accounting, making sure shipments arrived, etc. My friend who owns Wendy's pays his guy (who looks over the two stores) 125k a year for it. Thought that was pretty interesting.
TL;DR - big brands make big monies, obscure brands are hit or miss.
EDIT: Also OP if you were serious about opening either a Tim's or Wendy's (both are in the US, actually Tim's is picking up a very significant amount of marketshare there) I could get you on a call with the owner of either so they could give you their opinion.