Bakers can also keep baking but opt out of the Wedding Industrial Complex. I haven’t heard of anyone being unwilling to bake birthday cakes for discriminatory reasons.
Seriously, people who saw providing the trappings for wedding receptions as some kind of a calling in support of solid marriages are at a serious crossroads. Secular law has chosen to recognize as a marriage even more unions that the Church does not recognize as marriages, and this time recognizes unions that distort the meaning of marriage itself. Those of us who built careers wholly or partly based on the true meaning of marriage are now confronted with whether or not continuing in their professions will require what they feel is complicity with an evil.
I have sympathy for that. When in the world, however, we are bound to follow the laws laid down by legitimate authority, unless we truly have no option open that reconciles our faith and abiding by civil law. Some of us are going to feel we have to change careers or our business plans in order to accomodate both, sometimes at a great personal cost.
There is no help for it, though. Accepting the wrong-headed choices of others is the price we pay for being in a society where others are forced to accept what they believe is our wrong-headedness. There will be no ultimate Judgment of who was really right and who was really wrong-headed in this life; that is why this is a vale of tears.