The verdict
If you sell software or digital products to customers across borders, I'd pick Lemon Squeezy. The tax job alone justifies it. If you sell to consumers, or just need to be paid fast with a link or an invoice, I'd offer PayPal.
They are not exclusive. PayPal is often an extra payment method next to the main checkout, because many buyers trust an account they already have. I would not use PayPal as the only payment layer for a software business that scales. For Dutch customers, remember that iDEAL usually matters at least as much, and it has its own fee.