Hello,
If you have websites with templates and extensions that are not available for J3, the only thing you can do is to somehow change these templates and extensions with those that are available for J4. As Joomla team promised, upgrade to J5, J6, etc. will not be complicated. So, making these websites compatible with J4 is necessary now, but you won’t experience troubles in the future.
On the other hand, conversion from Joomla to WordPress will be a much more complex process, especially for large websites.
Regards,
Milos
