In 2017 and 2018 we made a lot of improvements to facilitate jQuery 3, so if you use the latest version of the controls you should not get such errors.
The problem you would face is what we encoutered when we upgraded to jQuery 3.3.1 - its 'use strict' breaks the MS AJAX framework under Firefox and many postbacks will no longer happen, but will throw errors: https://www.telerik.com/forums/known-issues-and-important-changes#KKI7NGE4P0K-jwQGL525dA.
So, for R2 2018 SP1 we reverted to 1.12.4 to avoid the "security issue" that exists in 1.11.1 and tends to get us flagged (let's leave off the debate whether it is a real issue, since even the jQuery team did not believe so but caved to peer pressure): https://www.telerik.com/forums/known-issues-and-important-changes#gDubpuLex0i1EeFOgoSbyQ.
With all that said, if you do not disable the jQuery we bring (https://docs.telerik.com/devtools/aspnet-ajax/controls/scriptmanager/disabling-the-embedded-jquery), our controls will use it and will keep working without issues. This will allow your project to use jQuery 3 for other tasks. If you want our controls to use the newer jQuery, the options and caveats are listed above.
Get quickly onboarded and successful
with your Telerik and/or Kendo UI products with the Virtual Classroom free technical training, available to all active customers. Learn More.