If your time horizon is short (months to a couple of years) going all-in with a vendor can work quite well. Over longer time horizons (several years or more), it's often not so great. Forgetting about the costs involved (i.e. they know they've got you) and the fact that if that one vendor ever becomes truly dominant that improvements will slow to a crawl (i.e. they know they've got everyone), there is a very real risk of whatever technologies you are depending on disappearing as their business needs will always outweigh yours. Feature velocity tends to evaporate in the face of a forced overhaul or even rewrite.
Pricing changes are a real issue. Google maps spiked in cost and those who were using leaflet JS just had to change a few settings to switch to another provider. Those who built using googles map js are locked in.
Yeah...We had a fixed yearly price for Google Maps API Premium account - when they switched us to PAYG, our costs increased 8x...Spent 2 weeks of unplanned urgent work switching to Mapbox for 3x of original cost...
