Everyone's locked into a vendor at some level or another. Want to move off of Oracle? It's work. Want to move off of servers and into VMs? It's work. Do you want to move off of some Java library like Spring? It's work. Even moving from apache to nginx is work (assuming you're not just serving static files).
Your technology choices always lock you in. You can minimize the cost of moving with architecture, but there's only so much you can do.
The key isn't avoiding vendor lock-in, it's understanding what the tradeoffs are for that lock-in and making sure it's a decision instead of a by-product.
It's like writing your stuff in NEW_TECH_LANGUAGE. Sure it might give you better performance, but now you have a bunch of deployment and maintenance headaches, and your people will cost more and be harder to find. And does it even work/scale in production/HA? How do you monitor it? What kind of weird runtime things are you going to get abused by?