Halo 5 was my third Halo game and I personally think it's better than some other Halo games. I see all the flaws and other things but I loved the way most armors looked and how you could intertwine armors and helmets. Sure it lacked total construction of suits but Infinite has a way worse way of getting literally anything.
Having to buy everything in Halo Infinite for customization is a big turn off. I have to buy the Pilot Helmet with the rest of the unnecessary armor pieces for $20ish bucks. If it were a system that I could buy the singular thing for $5 then I can get behind it. At least in Halo 5 I could play any game mode (outside Custom) and get points to get more armor.
In my opinion, Halo 5 was a great game! The campaign in 2015 had missions that were taken out a few months afterward and it made me a little upset because it added more things to do. I see why people don't like the campaign and I myself don't like it, nevertheless, it's still fun.
I wish more people played it now because it seems that I'm the only person doing ranked and the only UNSC/ONI Personal in the customs. I agree, people leaving and lagging others out isn't great, on older consoles. I know, people abusing the trait system (Deathless) and glitched weapons were not fun. Nonetheless, I sought after competitiveness in the game because there were many types of players and skill levels that really put skill into playing.
The Warzone mode was my favorite part of the game. You could go against other players for points or just eliminate A.I. for 5 waves and get massive amounts of potentially unnecessary XP and Req points. The Mythic extra was a great addition by adding skulls to Legendary enemies for a great challenge and more meaningless XP.
I see why people hate it but it's definitely Top 5 and maybe even Top 3 for me. I can't wait for more additions to Halo Infinite and the new Halo fan game: Branching Sickness!