If you get a call for TR course the chances you are getting hired are 99% unless you screw up your type rating by bad performance or something else, I never heard of somebody who did the TR and didnt get hired, but its common that people tell those bad fairy tale. Everybody here is grown up, a pilot and hopefully can do a profound research and choice. In the current situation you can call yourself lucky to be flying, even if the conditions are bad. I was in Ryanair and joined airbaltic last year and lost the job due to the lockdown. I changed my airline at the worst possible time. But who knows that, everybody is making assumptions that this and that could happen. Just wait and see.
For starters Ryanair is a very good school, you learn so much, the training department is top notch and depending on the base you have alot of destinations. And the conditions are well lets simply put questionable, depending on which employment you get. Ryanair contracts are generally good but contractors are horrible, but in corona times what choices do you get. If you get the opportunity, take the chance and learn from it.