Now the difficulty has reduced, computational power to mine a block will reduced if the Bitcoin price doesn't drop significantly, i don't think there will be a downtrend.

I guess you meant danger to decentralisation, I still doubt that because even if the big company do have a greater hash rate than others the probability of them being able to act maliciously is still low.

This is exactly the same thing I pondered so hard about... If my memories can serve me well, I think I wrote alot of about it already.
Most independent miners quit as it becomes impossible to make profits - especially after every Bitcoin halving. Just imagine going back to the usual 25sat/Vbyte and a ton of electricity consumption and expenses, roughly beating down the general revenue....  Just appalling!
Not totally! I guess the companies would have the upper hand now.
Decentralization? Could you at least be precise on which area? If companies are diving into the business of mining coins at a cheaper rate, it's because they perceive it to be profitable.. That has nothing to do with decentralization.

Has nothing to do with the lows are more to due with the havling and contracts.
There were (are) a lot of miners in data centers that are under contract to be there. And....wait for it....they pay no matter what.
So you can either pay a lot and run the miners at a loss or pay a lot and get 0.
I am sure many of them timed their contracts to end around now. April 1 or April 15 or May 1 or May 15 kind of thing.

So we may see another drop as the last of them are shutdown and retired.

*With my own eyes I saw 300 Amps of gear being taken out this last weekend since their contract ran thought the May 1 (last Wed)

-Dave