Level 4 enconter challenges a level 4 party now - good (a.k.a intuitive)
Sort of... what if you want the dragon to have backup, or minions? The system has repeatedly said we should be having encounters of level +1 to level +3 to challenge people, and that an even level fight is a relatively easy fight that will eat up some resources.
Just bashíng and not moving will bring hurt - good
Overly simplified analysis. Some groups may have literally nothing they can do about it. It's not like you can shift away after your turn to avoid getting hit when _you_ hit it, and it's not like the prone guys from tail sweep can avoid being adjacent, or the unconscious allies the dragon is standing next to...
Action economy will be working - good
On the monster side, this is true. This is a very good thing - its shroud might potentially be worse on a player-side action economy than the frightful presence was. That one is trickier to guage.
defenses are hitable for a right levelled party - good
combat gets more brutal when the dragon is bloodid - good
Both good, though again the method to get there may not be appropriate for all parties. You're missing the fact that the objections are not with the concept behind the changes, those are largely getting applauded, but with the actual math behind them that appears to be overboard.
HP are on a reasonable level when the dragon faces 5 players of level 4. The dragon will last no more than 5 rounds.
If they're having to use thrown weapons because they can't melee, this might not be true. Also, you may not be factoring in the -2 attacks from shroud, nor how often party members may be down. This could easily go more rounds.
why do you insist, that a second lvl party should be able to beat it down?
Cause the DMG says it should work that way, and all of the other monsters work that way? I mean, just putting it out there.
Only if all of the other monsters are also changed to have a high likelyhood of TPKing at n+2 is it really appropriate.
edit: scale it down to 2nd level and you are fine. I guess, even level solos being actually dangerous is a feature, not a bug.
Not necessarily - that doesn't make a large difference in its damage.
How many normal monsters worth of threat should a solo be? Ie, should a group be able to do an n+2 encounter with non-solos with the same danger level as an n level encounter with a solo? In what way is that good design?