That's one way for looking at it ... another is that Defender blocked almost 9 outta 10 "0-day malware attacks, inclusive of web and e-mail threats (Real-World Testing)" ... now 90% and 145 blocked attacks sounds pretty good until ya think about the fact that 18 of the163 threats got thru. So it's all relative to what you are putting at risk . My kids biggest worry is pics of the GF, their Steam library and a few other odds and ends, mostly school and work related that they have backed up to my server. They can easily restore 98% of their stuff by downloading, restoring from their phone or itunes library.
I have 32 years of business records, building plans, specifications , legal documents, tax documents and all the family personal valuables.
My outlook is, it's gonna cost me about $10 for 3 boxes to keep my systems safe for the next year. My 3 kids will chip in another $10 to cover their boxes, not so much cause they need it, but for $10, it's not like it's a big deal at less than a penny a day.