What are pros and cons of Ola’s scripts vs using maintenance plan?
I have written here 


  Maintenance plans are not bad, but when your environment grows, the limited flexibility and functionality that maintenance plans provide wont be sufficient.


To add more,


Ola's maintenance solution is widely accepted in the community and large organizations.
Its open sourced and issues can be raised at github/issues with a likelyhood of getting it fixed very fast.
Its flexible and scalable (even if you want to deploy it to 100s of servers just use Install-DbaMaintenanceSolution from dbatools.)
Microsoft took almost a decade to fix Maintenance plan GUI which was buggy itself :-)
has extensive documentation and FAQs and is constantly updated to accomodate newer sql server versions.
in preview version, you can even run backups in parallel.
for index maintenance solution, you can even time the process e.g. if it runs more than X amount of time, abort it.