why titled players don't accept random challenges

Because many of them are actually trying to improve their own chess and they can't improve by playing low rated players. 

Plus, they get so many random challenges.   Everyone wants to play a titled player to claim some sort of scalp.  

You, I see, are taking a different approach. You are asking the titled players to message you.  Let us know how that works out.

Many of them were available for games during the recent leagues competition.   Some of them played arena tournaments every day.   With few people in their rating class, they ended up playing a lot of low rated players.

You can have a chance to play titled players who are streamers pretty easily.   All you have to do is subscribe to their stream.

Yea actually many titled players are playing in the arena tournaments but even there I think you need to have as close rating as possible to pair with them and it's kinda boring to play a tournament abt 1 or 2 hrs long hoping to play with them

So practically none of the available high-ranking coaches will accept any invitation from someone whose ranking has not reached 2000? It's a pity, for a player who has been doing very well lately, such a game with a real champion would be an incredibly developing experience.
I completely understand, if I were a successful player, I wouldn't want to waste my time playing with someone whose ranking is only 1000 from chess.com. The same with checking the last games of the player who sends the challenge.
You just have to increase your ranking and then bother the professionals
Game vs GM is an AWARD for typical chess.com player!

I tried to challenge some grandmasters in chess.com for a 7 day non-rated daily game. I searched for them in the grandmasters list. They did not accept nor decline it. They just ignored it. I challenged MagnusCarlsen, but he did not accept it.