iPad won’t load app’s quickly

Check to see if you have enabled iCloud Private Relay. This feature has been known to cause all kinds of browsing and performance issues; if use of this feature is preferred, initially disabling the feature will reset associated routing - and may clear an associated problem:

Settings > [Your Name / AppleID] > iCloud > [iCloud+] Private Relay > Private Relay - set to OFF

You may have a related feature enable in Safari:

Settings > Safari > [Privacy & Security] Hide IP Address - set to OFF

After disabling the settings, perform a forced restart of the iPad:

Force restart iPad (models with Face ID or with Touch ID in the top button)

If your iPad doesn’t have the Home button, do the following:

1. Press and quickly release the volume button nearest to the top button.
2. Press and quickly release the volume button farthest from the top button.
3. Press and hold the top button.
4. When the Apple logo appears, release the top button.

Force restart iPad (models with the Home button)

Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.

Out of interest, which model of iPad Pro do you have?

As an observation, memory management within iPadOS 16.4.1 does appear to have some issues - which do have noticeable performance impact, in particular when switching between Apps.