It gets better: the linked Chrome feature "Cookies default to SameSite=Lax" mentions a bug in Safari (fixed in a not-yet-released version) that causes cookies with "SameSite=None" to not be sent in cross-site requests. So when Chrome 80 comes out, your options for setting cross-site cookies will look like:
* send nothing, and break in Chrome 80+ because of the new default
* send "SameSite=None", and break on any Safari besides the latest because of the bug
* send anything else, and break because that's what SameSite does
* send nothing, and break in Chrome 80+ because of the new default
* send "SameSite=None", and break on any Safari besides the latest because of the bug
* send anything else, and break because that's what SameSite does
Heckuva job, Chrome team.