I know the EE3 Relationship fieldtype is now more powerful.
Does Playa 5 for EE3 still have advantages compared to the new EE3 Relationships?
Is Playa 5 worth it?
I haven't used the latest Playa but the with relationships being native it will stop painful upgrades to the CMS whenever you next upgrade - it's almost always better to rely on core modules then to introduce 3rd party modules.
Also, if you want to switch to relationships then follow this simple guide: How to move all Playa relationship to EE relationships