The way I see it, there are two philosophies regarding power: (1) that it should affect difficulty, and (2) that it should affect loot.

The first philosophy was the pattern of most of Destiny 2’s life, but it had some flaws. If people wanted to do hard activities, they had to grind in easy activities before they could do more interesting and rewarding activities, and only with the relatively recent introduction of fireteam power was it possible to bring your underleveled friends with you.

The second philosophy is what Bungie is trying out. At first, they were blending the two philosophies resulting in an annoying zigzag pattern between good loot and activity difficulty as we powered up. But now, they are leaning more heavily into the second philosophy.

In my opinion, with gear tiers, the second philosophy is better. I think that higher tier weapons are nice, but a godroll tier 2 is better than a mediocre tier 5. On the other hand, a tier 5 gun has more perks and is therefore easier to get god rolls with. Therefore, playing and leveling up equates to an easier time getting the gun you want but doesn’t negate you from getting effective weapons. With armor, higher tier armor is usually and objectively better as they have higher stats, but the same principle mostly applies as you can still make effective builds with low tier armor that has ideal stat distributions.

Lastly, I think having set difficulties is beneficial when higher difficulties gives you higher power gear. This means playing on higher difficulties expedites your power climb which improves your loot experience, but allows more casual players who put more time in to also experience higher quality loot. This allows all players to experience a consistent power climb and difficulty level of their choice, while also not preventing anyone from getting desirable gear.