I run a small engine repair business on the side (weekends) and it really depends. Older well made shit will always win in my book, you just have to maintain it and repair it with good parts. Upgrading old snowblowers with newer more reliable engines and putting in the impeller kit makes them way tougher and better performing than any of the new stuff. Unless you buy top of the line Ariens, Honda, or Toro (which are expensive) the new box store shit will be WAY worse in 5-6 years than any of the old shit I work on. The metal is flimsy, and instead of dealing with broken starters (which are 20+ years old anyway and need maintenance) you have major problems like broken flimsy gearboxes, snowblower frames that crack around the POS welds, transmissions that fall apart and cost more to fix than an entire new machine, etc. If you own an older machine that is well made from a good brand, you'll have to do some maintenance and repairs to get it up to par, but it will be worthwhile and outlast any of the new box store stuff.
A lot of the new stuff I've had to tell customers to just go buy a new machine, because the repair cost exceeds the value.