Yes, there are always ways to lock yourself in. If you only use features supported by multiple browsers and consider the https://en.wikipedia.org/wiki/Lindy_effect, you stand a decent chance of long term survival. What you sacrifice is efficiency and polish, which are important, so choose wisely.
Rose tinted glasses.
There was a time not too long ago where IE6 was virtually required because of activex, vbscript, ie specific markup, etc.