In this was in previous gens, then yes absolutely and often times, it is a necessity. Hazards affected everything they could affect except for those with magic guard. Often times, it puts Pokemon into range of certain attacks. For example, spdef Hippowdon can normally take an sd boosted Garchomp earthquake from full health but if it takes three layers of spikes and stealth rock, it just straight up drops. Not only that, hazard setters in ou are Pokemon that naturally fits on teams. Think of Garchomp, Heatran, Landorus, Ferrothorn, whatever. It's not a question of whether hazards are worth but more of why wouldn't you want to to set up hazards
Since you mentioned ou, a singles format, a fundamental part of it is switching and entry hazards punishes you for switching. If hazards aren't on the field, many Pokemon become nigh immortal by mindlessly switching especially regenerator Pokemon. However, with hazards on the field, every switch has to be a calculated move. If you mindlessly switch your Tornadus into a Mega Medicham zen headbutt or ice punch, you just might die the next turn to bullet punch. In short, it limits a player's ability to endlessly switch because their Pokemon would take damage every time they hit the field and even if they switch into a resisted move, they would get worn down to the point where they wouldn't be able to take those resisted moves
In gen eight ou however, entry hazards, while still very important, have lost a lot of their value because of an absolute bs of an item called heavy duty boots. An item solely added to the game so that gamefreak's precious gmax Charizard doesn't die to stealth rock. This item has allowed several Pokemon, most notable Tornadus if it doesn't get knocked off and Tapu Koko, to switch non stop in the face of endless hazards. Several rock weak mons have enjoyed this dumbass item like Zapdos, Weavile, and during the early crown tundra days, Moltres. Despite that, setting up entry hazards are still very much worth setting up because two of the tier's best mons are neutral to rocks, Landorus and Heatran and even those that resist rocks like Garchomp and Ferrothorn could still be subject to be put in range of certain attacks although that is more difficult since they commonly run lefties which heals off rocks. However, unlike in previous gens, you often times need to only put rocks when you really need to or when you have a free turn
Spikes is a different story and it usually takes a backseat to rocks in previous gens because rocks affect everything but magic guard mons while spikes only hit those on the ground. There were some very good setters like Ferrothorn and Skarmory but depending on the team, they also serve as the rocker and between spikes and rocks, rocks usually takes the cake. Now in gen eight, spikes are often times more important to setup because it really wears down those rock resistant mons that I mentioned and more often than not, rock weak mons are gonna carry that dumbass boots. Still, this does not devalue stealth rock and moreso puts it as you need to calculate which hazard you need, assuming you have more than one, instead of just spam click your stealth rock button all the time until it breaks
Toxic spikes is also a different story but it takes more of a backseat because in previous gens, there weren't that many good users of the move and when a good user was introduced, Toxapex, it was a poison type. It wasn't uncommon to see toxic spikes get removed immediately because Toxapex is that common and now, galarian Slowking has joined the fray making maintaining the thing much more difficult. Pex also can rarely fit it into its moveset since it wants like ten moves to run
Another factor that makes them a near necessity, especially before usum, was that there weren't that many good hazard removal options. In gen four, it mostly became a hazard war afaik and in gen five, only Excadrill and Tentacruel are good spinners. When defog was buffed to remove hazards on your side of the field, there weren't that many Pokemon that could use it and without permanent rain, Tentacruel fell out of favor and leaving only Excadrill and I guess Starmie. In usum, just about everybody got defog. Tornadus, Landorus, Rotom, you name it. Hell even fkking Serperior gets defog because logic is brilliant. This made it much easier to defog but not so much to remove it entirely because with z moves, rockers often have the ability to straight up kill the defogger. An example is Garchomp with rock or dragon z move that destroys most defoggers. In gen eight, the current meta usually has only Landorus and Tornadus as the great defoggers and that's because offensive Heatran became the best rocker and it greatly mauls those two and led to the decline of Corvibirb
These could be outdated but here are two areticles that explain why hazards are important. They don't cover gen eight but they do cover the idea surrounding them
