I've relied on European trains plenty for weekend trips and they're still solid most of the time, though yeah, strikes happen more often than they used to - France especially seems to have them pop up without much warning. That said, a rail pass is probably still your best bet for a month-long route like yours because you get flexibility and can hop on local trains without buying individual tickets, whereas budget flights tie you to specific airports and schedules. Just build in some buffer time for delays and check the rail operator websites a few days before your trip to catch any announced strikes. The pass pays for itself pretty quickly if you're doing multiple countries, and you'll see way more scenery than flying point-to-point.