Yeah I mean I plan to be consulting or a CTO or something by that age. Unless you are crazy specialist I think you need to branch out into strategy or have enough reputation and connetions to earn silly money freelancing.
It's not possible for every 25yo programmer working today to become a consultant or CTO by the time they're 40 (or in fact any age). There's just not that many CTO/consultant jobs!
Similarly, not everyone can become a project manager, product manager, head of engineering, or whatever.
So as you age, you can take one of those career changes, or just ... find a long-term niche and stick there or keep up with what's new, and sell your experience.
There is a world beyond single 25 year-olds working stupid hours in startups.
I'm 41. I am doing just fine as a software engineer. I'm making a fairly ok rate for a MSc in my market (North-Europe).
I don't known what it means "older devs have it harder". I am a valued contributor, and if something bad would happen I have a pocket full of leads where to find next gig.
You have to maintain your career - nobody is going to do that for you. So yes, you have to figure out how to become a valued contributor.
Make sure your CV communicates you are "smart and gets things done" and you are set, more or less.
Perhaps software engineering is a bit more fragile than other more professional fields as there are lot of young uneducated employees who can be abused and exploited by unscrupulous employers. But generally you learn to identify those, and with a good CV of years of successful projects, you can find agreeable employment in most market situations.
Many plan to be a CTO, VP, or making silly money somehow, but that doesn’t often happen. I know few old developers, but those I know aren’t making silly money- they’re either in slow very small businesses or working for some mid-sized to large company.
I am already earning money that I would expect to earn only close to my retirement in my other careers, if successful. So I am very happy with my choice financially-wise. And I still enjoy a lot coding everyday. Also I am lucky to never have felt (or at least noticed) the effects of ageism on my career. On the contrary, employers have explicitly told me that my long professional experience and maturity was an asset that was considered in my hiring (they paired me with a 21-year-old who was a senior by technical merits, but still needed to improve in other aspects of fulfilling a senior dev role).
In my experience, there is a class of small company that has roughly 3-7 employees, at least half of which are 45-65 years old, where the business is slow and quiet, with little sign of any growth, typically selling a niche product or technology for which there is not much competition. One or more may have big ideas but really they just are happy having a job and working with others.
