The topic Latest Modem is certainly an interesting one and should not be neglected.
However, only relatively recent models like the Samsung Galaxy S9 will get “regular” modem updates from the manufacturer.
A Galaxy S5 SM-G900F with last StockROM 6.0.1 and update from 2018-03-19 (DBT) for example will not get any modifications from Samsung anymore. With the version CP (Modem) G900FXXU1CQK3 is over. Nevertheless, this phone is and remains a very much appreciated phone for me - especially since it is operated with /e/ 9-Pie.