[ido]

    there are many companies and roles which require you 
    to show the actual number of users, or the load of the
    service that you worked on.

I got my first job as a programmer in 2001 and not once was I asked that. I'm sure they exist but I wouldn't count on that being so common as to significantly impact the OP's career prospects.

Two things I've most often noticed people care about when hiring:

1. experience with the exact tech / field that they're hiring for

2. having brand-name job experience (google, amazon, etc).

It's sad but you'll probably get better mileage from having worked on a useless prestige/pet project at google using fashionable tech than a critical system written with JavaEE & serving a lot of high-value customers at Alliance Generic Insurance Services Corp.

[collyw]

That last sentence sums up the sad state of hiring in the industry well.

[yters]

probably depends if you are applying to another faang or if you want to work on mission critical insurance technology

people who really need skills are probably good at indentifying said skills

[cjvirtucio]

What happens when one is working on something that is neither of the two things in your last sentence?