Opting out of the razorblade industrial complex
Around the time the Mach 3 came out, I started ignoring advancements in razor technology. The latest thing from Gillette looks like Dyson vacuum for your face. There's a big roller ball in case your wrist is unable to rotate, and there's even a battery inside that presumably causes it to vibrate because... why not?
Buying replacement blades for an aging Mach 3 was the path I chose to take as generation and generation of new razor would come out, refusing to needlessly upgrade to the latest and greatest.
A couple of years ago, a friend of mine turned me on to shaving with a double-edged safety razor. Since then I've discovered there's a thriving community on reddit for people who shave with straight or doubled-edged razors.
The double-edged safety razor design was actually invented by Gillette in 1901 and the company was awarded a patent in 1904. Gillette got a contract to supply the US troops in World War I which brought that style of razor in to common use (via Wikipedia). These days there are lots of companies manufacturing both the handles and blades. No more patents mean no more vendor lock-in. Gillette to presumably keep a stream of revenue has gone off the deep end iterating on a solutions that already do the job really really well.
Competition on the now generic double edged safety razor has driven down cost that you can get replacement blades for about $0.10 a blade.
Shaving with a straight razor is a bit more up front, but in the long run you won't need to replace the handle (ever?).
One thing I noticed the Merkur handle does differently is slightly curving the blade using some pressure from the razor. This makes for a really great shave that is hard to nick / cut yourself.
There's no more satisfying way to shave than putting a heavy piece of metal against your face with a big ass blade in there and shaving off some unwanted facial hair.