A good percentage of emergency services are encrypted, but not all. It varies state to state and region to region. Without knowing your location it makes it hard to confirm details.
While encryption has had an impact on scanning, especially for those who purchased a unit to "listen to the coppers" and are now denied that avenue. Others like myself who have been into radio for excess of 50 years, you can find other services to monitor. As to private businesses, the rollout of digital platforms like DMR & NXDN has made encryption (actually called privacy on those modes) easier to implement. Basically the tick of a box in the software enables privacy. Again there are those who use privacy but in the overall scheme of things they are few and far between. Analog users really only have voice inversion scrambling which is rare these days.
The internet, is a double edge sword. It has meant the dissemination of information in literally seconds. But it has impacted the hobby in ways that were never contemplated. One of my pet hates is streaming. Why invest in a scanner, bother to learn the structure of the radio bands or even the basics of radio when you can listen on your $100 mobile phone? It is demonstrably the case, mainly in the US, that streaming has lead to departments and agencies enabling encryption because rather than their communications be isolated to a town or city, they are now state, country and world wide.
As to buying a scanner or SDR, buy both. Don't spend $900 on USDS100 to start with. There is more than enough good used scanners on the market, in some case for hundreds of dollars less than retail. They are perfect electrically and physically. The SDR is used as an enhancement to a scanner rather than an alternative. One compliments the other.
If any 'new' communications mode is impacting scanning it is not encryption or digital or trunking, it's PTT or POC, Press To Talk on Cellular. Basically a radio on the mobile phone bands. One hundred percent secure and provides coverage a radio system could only dream of. And while it is gaining in popularity it is not widespread. Like any 'radio' based network it has limitations, with some users swearing by it, while others swear at it. Time will tell.
Here, we have had some changes. Compared to 2016, I have seen these changes to business users:
25% of business users have gone off the air totally, this is moving to tablet based solutions or not using radio at all.
25% have moved to DMR or NXDN
50% are still using FM voice and can be scanned.
Our emergency services have gone 100% encrypted.
Air band, marine, amateurs and UHF CB can still be easily scanned.
