It doesn't have a single advantage going for it under any circumstances. Being a pike-nose "heavium" is already inherently bad tank design because it removes angling as an option and heaviums throw away all the benefits of being one class in order to have all the drawbacks of both classes. Add to this the fact that the turret roof is too massive for playing hull-down to ever work, the mobility is average at best by tier 9 standards, the gun has penetration and accuracy so god damn terrible it makes German 88s and American 90s look good, and it can't even try to reverse sidescrape because of the angled rear corners (not that sidescraping is even an effective tactic in 2021 anyway).
And yet there are people who swear that it's a good tank when it clearly isn't in any way. There has never been a situation where anyone would say "if I was in a T-10 I could have won this." The 277 had better be worth drudging through this pathetic excuse for a tier 9.
Source: https://www.reddit.com/r/WorldofTanks/comments/qmz2cg/how_do_people_call_the_t10_a_good_tank_with_a/