Seems going into IT may be more financially rewarding for someone later in career. OP could probably more easily pivot to being an application SME for something fintech or maybe mech-E related than a SWE.

But I am curious myself too. I’m hitting 40 in a few years and will have 10 solid years of IT at that point. Programmings always been something I’ve dabbled in on the side. But I know that market has ageism probably stronger than in IT.

What is an "application SME"?

doesn't IT include SWE? like IT is everything tech related?

Not in common usage within the US tech industry (by this I mean technology-first companies, not just companies who happen to have some developers). In those companies at least, if you say you want to get into "IT" people are going to think you mean tech support, system administration (generally for internal systems), etc. I don't know any professional software developer in one of these companies who would say they are "in IT." (Yes, it's a huge industry and I'm sure you can point out exceptions.)

IT doesn't have as much dev as it used to - the amount of business functions that can be handled with affordable SaaS products takes care of a ton of software needs for many businesses. There certainly still are developers in larger IT shops, but anymore you get more "Business Analysts", who configure and maintain SaaS platforms, maybe with some light scripting and coding, instead of a team of devs writing code from scratch.

'Functional Analyst' is the usual term if you're looking for jobs in this space - heaps of jobs in Salesforce/Dynamics/SAP/etc - surprisingly good pay in this area, but not really the start-up life.

In a software is eating everything world, I want to retrain to learn all skills needed in IT/Programming to remain relevant.