But who is encouraging you? Since in Europe/Rest of the World(except US/UK) companies never mention how much they're willing to pay and even the recruiters they hire are sometimes not allowed to mention the upper range to their candidates. So nobody knows they're underpaid unless you're willing to take your free time and apply to jobs, contact recruiters and go interview at a few companies and go through some rounds of negotiations.
And even then lots of companies will look at your application very suspiciously that you're applying to new jobs so soon and they'll expect something's wrong with your relationship with your current employer or with you so some might not even make you an offer.
For most senior employees with families that's a lot of trouble to go through so they don't even bother unless a recruiter knocks on their door with the offer of a lifetime.
If companies had pressure to give raises internally, this would give less reason to hop jobs. I think that's a good thing for mostly everyone (including their employers). Everyone except dirt cheap shops where nobody wants to work anyway if they have choices.