Comparing my experience with Cisco B and C Class, HPE DL and Dell PE server experience over the past 20 years:
Cisco: Expensive, Good support/service during lifetime of product, excellent management tools w/o buying additional lics, reliable, but eosl/eol is short and poorly supportable after.
DELL: Just retired some 30 of their servers and storage. No regrets. Expensive, horrible support, licensing is a nightmare, but e360 and online tools were better than others. EOL/EOSL support is okay for a max of 2 yrs afterwards.
HPE: Just deployed 20 DL380G10+, Cheaper than other 2, licensing is a pita, support is meh, but InfoSight and support costs are cheap and there’s good support past eol/eosl.
I’ve done the whole white box thing like SuperMicro a number of times and while it is cheaper upfront, it’s a headache over time.