I've been around plenty of people who haven't used fancy bowling shoes and I personally haven't either and have never had any issues. I've watched plenty of old timers who never had fancy shoes and been bowling for decades and never had issues.
I'll say again if there's pre-existing medical issues that's one thing but if nothing's wrong, it's not a big deal. A shoes a shoe. Spending $100+ on shoes isn't worth it if you're not bowling on tv every Sunday.
Maybe you've just been lucky?
I've bowled at places that, when it's humid or rainy, I've needed to use Easy Slide on a Dexter #12 sole (called Black Ice) on every shot, or I'd stick at the foul line. One day during practice, I went thru a full bag of Easy SLide to bowl 3 games.
Most places are not that bad, but there is a huge range of slide and stick between different synthetic approaches and different wood approaches. Some are maintained well and other are just maintained differently. Without adjustable soles and heels, I wouldn't be able to bowl at many places. One of those was Nationals about 15 years back - zero slide and Easy slide was prohibited.
Maybe you have just been lucky but I and many others need adjustable soles and heels in today's wide range of conditions and environments.
I don't notice it as much anymore with approach conditions. Everything around San Diego is synthetic or at least newer wood.
But growing up, when I was in suburbs of Cleveland, bowling traveling league I'd see a lot of varying feels on the approaches. It was all part of the challenge. Had to adjust to the lane conditions as well as the approach.
Even like you said though, there's easy slide and other products that are way cheaper than a high priced shoe. But everyone is different. Personally I can put a $40 pair of shoes on or a $150 pair on and I'm not going to notice a difference.
My opinion and suggestion were based on me. I just noticed everyone else suggesting one high pair or another and was saying that you don't always need it. It's like golf, some people just get the high priced shoes, bag and clubs because they can. I merely stated that it isn't always the case.