Hate the new IOS update 26.2

With what, specifically, are you having difficulty? With some understanding of your issue(s), contributors here may be able to offer advice as to how you can address or mitigate particular areas of complaint.

Rolling-back to an earlier version of iOS/iPadOS is not possible. Having updated to iPadOS 26.2, you cannot reinstall iPadOS 26.1 or earlier.

All System Updates are digitally signed by Apple - and can only be installed whilst the digital signatures remain valid. After release of a new iOS/iPadOS version, the immediately preceding version continues to be digitally signed by Apple - however, usually within a few days, Apple will revoke the digital certificate with which the earlier version is signed.

If Apps no longer work properly following update to a more recent version of the OS, you’ll need to seek assistance from the related App Developer - as only they can resolve issues with their App.

How to contact an app developer - Apple Support

Perhaps consider that iOS/iPadOS updates include both functional and essential security updates. Restoring an earlier version of the OS would undermine the security of your device and your personal data. 

For information, Apple invite submission of constructive comments via its Product Feedback portal. For iPad and iPadOS:

Feedback - iPad - Apple

As LotusPilot mentioned, you cannot roll back to a previous iOS version. But the User Tip below may help you significantly reduce the Liquid Glass effect. It helped me.

Liquid Glass - Love It Or Hate It - It's … - Apple Community

This tip also made a good difference on my iPad.

Reduce Liquid Glass Effect: Fortunately, you can adjust this effect whenever you want. It should be turned on by default as soon as you install iOS 26, but you can tweak how transparent your iPhone looks. Here's how:

• Open the Settings app.
• Scroll down and go to Accessibility.
• Tap on Display & Text Size.
• Turn on Reduce Transparency. 

You'll instantly notice that areas like the Control Center don't have a transparent effect anymore, letting you experience iOS 26 without distractions.