We have noticed a very striking degradation in performance of all our 3G connections (multiple work and personal ones, on multiple mobile networks) in recent years, with a particularly obvious drop around the time 4G became a big deal. It could just be coincidental of course, because obviously in terms of radio signals they shouldn't interfere. However, our more cynical parts can't help wondering whether resources previously used to support 3G networks are being redirected over time towards the new and more profitable 4G services, leaving those still using the same 3G at the same price with fewer stations to connect with, less regular maintenance, etc.