Of the US based companies that make and sell rods in the USA the other 2 majors are G Loomis and Orvis. Orvis doesn't have the presence here in the west it does elsewhere. Two others to consider are Scott and Winston. Both offer lifetime warranties with no 'deductible'. They make excellent rods well worth the money.
The Sage warranty isn't any different than any other company. There is a $95 USD fee to repair a broken rod, if they will repair it under warranty. You have to ship the rod back to them. The warranty is only good for 10 years or something like that. Older rods it's $195 if they can actually still make the replacement section. If they can't they offer a current model at a discount.
Other brands are Hardy/Grey's (blanks made in S Korea or China), Douglas (US) don't know who makes their blanks and Loop based in Sweden, blanks made in Korea. There is also Echo though cost wise they are not up there. Very popular rods and worth looking at.
There is also a Canadian company Hall Rod Company, based in Ontario:https://hallrodcompany.com/collections/shop-all
I think you will have to spend a few hundred $ more to get a top of the line rod. The major difference is the quality of the components (guides cork and other cosmetics) plus the most advanced blank tech they have to offer.
I have been fly fishing for around 45 years and have only once bought a rod that was in the top of the line range. I have mostly bought used or mid range priced rods. I have tended to want a variety of rods than a few relatively expensive rods. Also let me acquire a nice collection!
You might also consider buying a blank and have a rod custom made by a local maker such as Dave Barnes, who does post on this website.