As far as I can tell, the first openly networked pacemaker was implanted in ~2009 [0] (Probably earlier in not-announced mode, but not by much). A decade and a half ago, people pretty much only had a home PC connected to the internet in their house. Now they have everything from their lights to thermostats to home security systems connected. 15 years ago, there were probably some internet systems with large collections of personally identifying information on them, but western society as a whole hadn't yet decided to put all the data one could want to know about them in one place (multiple times over).
Everything might be more secure, as you say, but there are so many more ways a small hole could be exploited to do damage now.
[0] https://www.popsci.com/scitech/article/2009-08/first-patient...