iPad Split-View in full-screen mode

You are not alone in this, but nobody at Apple reads this forum for feature requests. If you want the request in front of the product team, send it at apple.com/feedback, that is the channel they actually track.

Until anything changes, the closest setup is this: Settings > Multitasking & Gestures, and choose Windowed Apps instead of Full-Screen Apps. In windowed mode you can flick a window to the left or right edge to tile it to that half of the screen, or use the tiling options behind the green traffic light button, so two apps side by side like the old Split View is still doable. What is genuinely gone is the old full-screen mode behavior with the draggable divider and no gaps, there is no toggle that brings that exact version back.

Contributors within the Apple Support Community (ASC) are all end-users, just like you. Other than the site Moderators, Apple neither monitors nor participates within the Support Community. As such, anything that you post here will not be seen or acted upon by Apple or its Development Team.

Apple does invite submission of constructive feature requests via its Product Feedback portal. If you would like to see changes or additional functionality in a future version of iPadOS, this would be the most appropriate channel through which to make a request:

Feedback - iPad - Apple

While you are perhaps unlikely to receive a personal reply, we understand that all submissions are logged, analysed and forwarded to the appropriate team(s) for consideration.