Of course they do. But the real specialists will most likely have been able to keep themselves out of the on call schedule.

Only AOW (state pension) is a requirement by law and for full-time salaried employees there is no way around that. Private pension (what is meant here) is not required by law though financially very lucrative compared to doing it yourself. It can be made required by making a CAO (collective bargaining agreement) "algemeen bindend" for all employees in a sector/company but this is not always the case in all sectors (e.g. IT). Note that this is way more complex and this is just a simplification.

It's hard to find actual numbers. Tech jobs, smaller companies ("MKB") and work in the agricultural sector tend to have a higher percentage of 40 hour work weeks than other sectors.

Only 3% of the people in the Netherlands work 41 hours per week or more. The average Dutchman works 31 hours per week. (source https://www.cbs.nl/nl-nl/nieuws/2020/08/meer-dan-de-helft-we...)

I have been working between 30 and 24 hours as a Senior Software Developer in the past 20 years. I have had several colleagues who work a similar amount of hours. I have been telling employers that I am only productive for about six hours per workng day on average and that never has been a deal breaker. The number of productive hours does vary from day to day, but I know that I push myself beyond that limit, I will run in trouble after some months. I have heard about studies that the average employee is only really productive for about two or three hours per day. With me working six hours per day, I might just as productive as someone being eight hours in the office.

Most private sector tech jobs in NL are 40 hours per week. But many private sector jobs are also flexible in ways that I've never seen in the USA. For example, allowing an employee to work 40 hours in 4 days instead of 5.

Not very standard but if you want to work 36 or 32 hours that is possible almost everywhere (you'll just get 10-20% less pay).