FnF helicopters, other than maybe the Israeli AH-60, are not that powerful, as FnF missiles are still unreliable.
They are only really good at dealing with SPAA, although things like Pantsirs can still shoot them down, hide behind cover, and can even tank some of them.
Any map that has dense foliage or buildings often can render them completely useless, as tanks can simply get into cover without even knowing they’re even being fired upon, let alone have them hit the correct spot.
Can you name some?
F&F helicopters have a pretty low skill floor and skill ceiling, as you can only control them so much as when they launch.
Comparing with other helicopters, like ones with hellfires equiped, they have a much higher skill floor and skill ceiling, as they still have some control over how they guide in. You may want to stop using IRST auto-tracking when the intended target is near another vehicle, etc. If you’re even more skilled with them, you can lob them over mountains and use IOG for a while until they are close enough to the enemy - effectively making them somewhat of a f&f missile. However, this only works on some occasions, and is very difficult to do correctly. Not only that, most laser-guided missiles found on top tier helicopters are often slow and unmaneuverable, with little to no effective range. The only exception to this are the Mokopas found on the Rooivalk, the AKD-9 (trades damage and range for maneuverability) found on the Z-9WA, Z-19, and Z-10, and the AKD-10 (trades speed for maneuverability, damage, and 10km effective range).
Direct-fire ATGMs, like the Vikhirs, tend to have similar skill floor as the Hellfires, but have much higher skill ceiling due to their ability to go through foliage and smoke, and you do not have to rely on luck if the enemy so happends to pass them. You can even track them through smoke with the KA-52 using MTI radar mode.
This is why, to an average person, it makes sense that the AH-64D and Tiger UHT are at the same BR as the Ka-52, but does not really make sense when you consider their actual capabilities in competitive matches.
Ka-50s and Ka-52s in particular tend to be the hardest helicopters to play, and yet both are one of the best helicopters in-game - exceeding the capabilties of f&f and laser-guided helicopter platforms in most cases.
As for (top tier) helicopters being bad, they definitely aren’t as good as they once were, but they aren’t that great, especially when considering SPAA now get twice the number of missiles, the damage model changes, and the ever increasing air superiority provided by aircraft such as the Eurofighter Typhoon, and even things like the SU-34.
The ability to mark targets to automatically start firing upon them is a nice feature, but like @Славянский_Прострел said, experienced players already do this with other mechanics, like ‘attention to the map!’, drone pings, and yellow squadron markers. And this feature can also help inexperienced SPAA know where to look and expect helicopters (especially those who are coming from their helipads and straight into the battlefield).
