This is true, sort of. Age discrimination is different where it matters - the threshold to prove age discrimination is so high that the law could just as well not exist.
Unless you are in the US and are going to graduate university at 22-23 best to forget about a career in STEM. Not worth the effort and time. Milk has a longer expiry date than a STEM worker who's perceived over the hill late-twenties or early thirties.
Quality of life, say in Switzerland, (and I know this can be a hot topic that depends on personal preferences) is way better than basically anything US can offer for similar wealth bracket. That's my personal view, based on my personal opinions, evaluations and wish to give my kids the best and healthiest environment to grow up in so obviously not universally true.
Older dudes are definitely very supported here, but this is specific per sector/company. Average age of my coworkers (banking en Suisse) is around 45-50, all devs, admins, devops. We wanted to hire one 55 year old guy for dev position last week, we made him (a generous) offer already but he chose a different position. He didn't have the skillset list much bigger than what is flying around by OP (maybe some crypto stuff but we don't do it yet).
What you describe are mostly startups full of folks who want to get rich quickly, mostly fail, have attention span shorter than tick of second hand on my watch. You can find those everywhere. But that's a relatively small part of the market and at least here definitely not the best paying one.
Germany is where startups valued at $25bn and $45bn (Zalando and Klarna) are paying less than $100k for 10 YoE with >40% income tax.
Please let's not discuss already obvious things though I agree that Switzerland is better in terms of salary and taxes.
As per your own company you are using anecdotal evidence. Ageism in tech is very well-known and pretending it does not exist is not going to fix antyhing.
...by American standards. Ask anyone in Northern Europe if they are happy with their salary and they will almost say yes. It's America that is distorting everything with their ridiculous salaries.
In the US, we have the same laws. It's flat-out illegal to discriminate by age, as it is by race, religion, gender, pregnancy, marital status, etc.
Out of that list, if a company tries anything other than age discrimination, they are pilloried and investigated.
However, in the IT industry, age discrimination is actively encouraged. Companies write job ads that basically say "Bros only."
The story I hear, is that older folks are "just waiting for retirement, and won't be loyal." That's rich, in an industry that has been completely formed around the idea that engineers will stay at a company for no more than two years.
In my case, I had my retirement set, years ago, and would have been willing to work for half of what a lot of younger folks would demand, if the work was motivating, and the work environment was good.
I have an enormous portfolio of exemplary work. My skills are "five minutes old." I'm not some old duffer, sitting on COBOL skills (which, I understand, would actually have made me more attractive).
It's been my experience that no one ever bothers to look at the portfolio. They've already made up their mind, and the only reason they are talking to me, is to tick off an EEOC checkbox.