If it didn’t have icarus dash it would be just as awful as bottom tree, sure celestial fire is pretty good but that wouldn’t be enough to warrant picking it over anything else if icarus didn’t exist. The mobility the class alone has is the only reason it’s called “top tier” mixed with aiming while gliding and very few people even have the skill to use it properly and take advantage of its potential. In all my years of crucible I can count on one hand the amount of people I’ve encountered who can actually dash properly let alone use it in gunfights. Just because some montages on YouTube exist and some streamers say it’s the best means nothing to the average player who picks stasis at almost every opportunity due to its ease of use and area denial that top tree simply does not offer.