From the perspective of Dutch labour law and regulations it depends a bit if the social events are organised by the employer (with an actual or implied mandatory character), or if they are organised solely as social function by and for your fellow employees (but probably sponsored by the employer).
If such events are organised by the employer and your presence is mandatory (i.e. you are not supposed to refuse the invite or your presence is part of your role as a team lead or manager) typically the working hours law ("Arbeidstijdenwet") is applicable. That has a number of requirements and consequences, among others:
- You're by law entitled to a 11 hours of uninterrupted rest between shifts, i.e. if the event ends at 22:30 the next day you don't have to start until 09:30 at the earliest.
- When the employer sets working hours the employer must make a reasonable effort to respect your personal circumstances outside of work and your duties as a care giver, parent and your private life.
- You're not allowed to work for more than 60 hours in an individual week nor exceed 48 hours weekly when averaged over 16 weeks.
- IIRC when your income is below the level of the minimum wage times three (± €60.000,- per annum) those hours will be either considered paid overtime or part of your contract hours which can be compensated, rather than "part of your well paid job" or after hours in your own time.
- Collective Labour Agreements (Dutch: "CAO") may have different regulations.
In practice that means that most employers in The Netherlands take great care to keep the number of mandatory after hours events to the absolute minimum.
When the after hours events are optional, which is therefore usually the case, officially your lack of attendance may also not negatively impact your performance reviews as those are about how well you do in your actual job.
Of course the result may still be that you're also not considered exceeding beyond the expectations for your current job, which could be barrier for promotion to team lead / manager where such attendance might be a required part of the job.
As a native Dutch national with experience in a number of smaller and larger companies I think that Dutch work ethic is very much that a job is a job, it earns you a living, but it doesn't need to provide you with a life.
Many natives won't attend optional after work socials and, rightfully, expect that no reason needs to be given beyond that they simply don't want to. Or if they do attend, it will only be for a single drink (drunk driving is not only illegal but also frowned upon) and they are not embarrassed to leave again quite quickly.
IMHO People attend the optional after work socials because they either genuinely enjoy them, they don't have a spouse or children that require their presence at home (or they are avoiding those), they may believe that it is good for networking and their career or they don't yet have much of social life outside of work.
That latter category are seems to often be younger colleagues and expats.
Many expats remark that in many regards Dutch society is open en welcoming to them, but it is also very difficult to make Dutch friends and integrate more into Dutch society. If there are many international colleagues that may be an important reason your employer sponsors that many social events, to provide a substitute for the social lives expats left behind in their native countries.
If you don't need that, good for you and decline.