Question LCD display storage

I would guess it is mostly due to mechanical (physical) creep or warping.

LCDs can last quite a long time - I have some that still work OK after >30 years.

There is no experience of how long modern types of LCD will last (they haven't been around long enough).

You will need to consult manufacturers to get information about this and unless you have significant credibility (they think you will buy lots) it will be very difficult to get information and even harder to get a guarantee.

The actual life time of an individual LCD will depend on the underlying technology and the quality if the materials and production.

If you need parts with exceptional performance and quality expect to pay an exceptional price.

You can test parts buy exposing them to the highest safe operating temperature and measuring their actual lifetime, and then assuming that the life will double for every 10K cooler that they are actually stored at.

Why do you care - what is the application ?

If it's the countdown timer on a nuclear waste store - don't use an LCD.

MK

my electronics that use these IPS LCD displays are R36S and Powkiddy Q80 consoles and my storage conditions 34-36C 58-68%

cloudff7 I would be more concerned in the batteries.

i removed batteries and store

What are the conditions for long-term storage of 3.5" IPS LCD display to avoid loss of brightness and performance in LED backlight and liquid crystals confusing disoriented and slow and dead pixels?

cloudff7 With cheap chinesium there is no good storage conditions, more so for a long time. 

Those consoles are low-cost, they with have the cheapest consumer electronics displays, so you should set your expectations accordingly. In any case, there are bound to be better systems in the coming decades, so chances are high you'll still be able to play the same games if you want, even if it's on a different system.

I searched but I couldn't find the datasheet for the displays of these two consoles. Is there a datasheet for a low-cost 3.5" IPS LCD similar to these two displays to have storage information that is closer and similar to the display of these consoles?

cloudff7 Only reputable manufacturers use their ressources to test an document this kind of data.