To expand what Art just said about Sears Craftsman,
Sears (now owned by K-Mart) has always contracted with manufacturers to make tools for them. By the time they told the manufacturer what they wanted it to look like and what price they wanted to sell it for the manufacturer inevitably made it different from their own tool of the same production year. Some parts would be interchangeable with the OEM and some would be brand specific.
So, you see what happens ten years down the road. You might be able to get replacement parts from Sears but probably not. When you go to the manufacturer for an OEM part you might find it. You might not if it is one of those made only for the Sears model. This often happens with shields, handles, guides, etc. Then you end up looking for used machines to cannibalize in order to find parts.
While one of my hobbies is restoring old "tools with tails" I sometimes have to wait years before I find parts.
So... buy a brand name you expect to be around in 20- 30 years. If not for yourself then for the next owner.
Yep, thats why we see posts from people looking for NLA part for PC, Bosch, Makita, and others! Anything past 10 -15 years old is hit/miss at best... especially if electronics are involved. Many machines of most major brands last 15 - 30 years with no need for parts. My 18 year old Craftsman router and 35 year RAS are examples!
If you make your power tool decisions on long term parts availability... better stick with hand tools. This is getting more and more the case with global manufacturing and shorter model change cycles. NO
manufacturer will retool a production line to make you one part.
For larger machinery, there are some small 3rd party shops willing to manufacture parts. For smaller commodity tools, that isn't practical, again especially for electronic module like speed controls for routers.
How many cordless drills are laying around due to it being cheaper and quicker to just buy another? I would personally not make this my primary purchasing concern!