This was a pre-lit tree.  $400 - so not a cheapie.
Year 1 - one string burnt out.
Year 2 - one more string was burnt out when I set it up, so I bought a few loose strings and just over-thread them.  Before Christmas day, another string burnt out.
Last year, I cut out all the pre-strung (mostly euchred lights at this point), and bought all new lights.
This year, I decided to zip-tie these new lights permanently in place.  Won't know until next year if it actually was worth the effort.
This was my third pre-lit tree.  First one was great.  Second one was garbage, so I decided to buy a pricier model, which turned out to also be garbage.  Luck of the draw, I guess.