If every node enables pruning, new nodes won't be able to sync the chain on top of the genesis block, they would need to trust a third party to receive an updated chain. Practically if this happens (very unlikely in short-mid term) it will have disastrous implications on decentralization and security.
Afaik there are plans to distribute the block chain data on nodes to address the problem.

However there will still be the need to sync the entire history, which will increasingly uncomfortable in the future.
There is an interesting idea on a "Bitcoin Onchain Pruning" solution,but I don't know to what extent it can work.