Soon it is time, for Windows 7 the extended support ends on 14.01.2020. As with every end of operating system support the end comes “completely surprising”, okay, not really. At the beginning everything looks so far in the future, it is still x years time. But in the end, the problems appear.
I already saw this at the “surprising” end of XP. But there are also cases where migration is not so easy. Special problem areas can be interfaces to special Hardware. For instance, measuring workstations or production control systems. If a measuring instrument with current Windows 10 support directly costs a few tens of thousands of Euros, then you consider the investment.