Ranked matches in the "Higher Rank Festival"

I agree with your opinion. I have also posted multiple times demanding improvements and proposing specific measures to address the smurfing issue.

But there has been no response from the management. It feels lonely and empty, as if they have no interest in our cries of distress.

They need to massively increase kill RP in lower ranks, this will push these players up into Platinum in just a few games, and it will also incentivize lower level players to go for higher kill games in low rank to rank up more quickly. While still having the option to play safe and strategically and still rank up from that too.

This would solve the problem. It's unfair for low ranks to face these players. So that would be the easiest solution. Wouldn't stop smurfing of course. But they could even add a bigger point gain if someone gets 10 kills in lower ranked for instance, they could just give them 200+ more points to send them up asap to fight real competition just as a bonus for high kills and to stabilize the player bases across the ranks more quickly at the start of each season. 

There are tons of accounts (probably after a ban wave) with low levels, like 100, who are already in D3 and killing in split seconds.

Ranked games (especially solo q) are probably a waste of time.

Since D4/D3, solo q has become practically unplayable. When a teammate is knocked out in the first fight, it's usually game over.

There are few replicators, so it's very difficult to find a "clean" replicator.

The game looks like ALGS. 3rd ring - 15 squads, 4th ring - 12 squads.

Maggie is everywhere, Alter is everywhere. No one at Respawn has been able to knock Alter out of the meta for half a year or more. Defeating a squad is very difficult when someone has Alter in their squad, which is why we have 15 squads in the later stages of the game and play in the ALGS.

Well, I thought something had changed, but solo q is still unplayable in ranked (unless you're good enough to have been a multiple-time master/pred in the past).

Alter is extremely easy to deal with though. I see people rat and camp bad Alter Nexus placements in Diamond 3 ALL THE TIME! So it's not even true. 
It's more often the case that Alters are incompetent and place Nexus where enemy teams will rotate through and clearly SEE the nexus and camp it. 
In diamond 3 it's a LIABILITY to even use Alter Nexus. 50% of the time and I'm not even joking, my teammate will take other randoms nexus mid fight and die on nexus instantly. 

So no. Alter requires skill and game sense to actually understand where you can even place a nexus that will be useful. 
I even have several Alters in Diamond 3 who place the nexus too far away. They go to a fight. The fight is outside the range of their nexus that they just placed pre fight. And they could have saved the game with it but didn't understand not to place the nexus too far away XD 

Alter is not a problem at all. Her balancing is extremely good imo. Because when a character is ONLY good in barely 10% of the players hands, then you know that it takes skill and IQ to play it correctly. 
It's when a character is good in 90% of players hands REGARDLESS OF SKILL that you can say maybe they are OP. 

A character I would have guessed is OP is Valkyrie, but even with her buffs she still regularly gets nuked out of the air easily. The balancing is pretty good right now IMO. Nobody is really too strong. The top Horizon or Octane players can outskill almost any legend, but that's gunplay skills and movement skills, 97% of Octane Horizon players can't do that XD

Alter has been in the meta or close to it for a year and a half (since the sick Ash/Ballistic/Alter meta). Because everyone withdraws from the fight at any time through the Nexus - we play ALGS, not ranked. This is a fact and Alter, Maggie or Valk should get a nerf. But don't tell me that Alter is easy to play when almost every team has her.