Still, somehow it’s more true for php.. maybe because other languages invest more in migrating to newer standards. Maybe because so many projects are self-hosted by non-programmers, in which case it makes sense to be conservative
Can you name one or two "newer standards" that "other languages" have invested more in migrating to, compared to PHP?
Did you mean standard, as in HTML5 or ES6? Or something more like a fashion or fad, like FP or OOP (which PHP has had for a long time)?
People ask the same old questions about PHP on StackOverflow et al. because a lot of people start with PHP and as beginners they will have the same questions every beginner had before them, and the same lack of ability figuring things out themselves or finding their questions already answered. That has nothing to do with PHP per se except that PHP offers a very easy on-ramp to getting started with web development, so a lot of newbs start there.
If you look at the W3Techs methodology, posted on their site for all to see but apparently few to bother with, you will see that self-hosted hobbyist and learning projects aren't going to make it into their results.
