It's impossible to predict the state of the industry in four years and what options are available. I think its even impossible to predict what it will be like next year especially in Europe.
At the same time, unless you have been selected by an airline through an integrated route it's always (certainly in the last 5 years) been a punt to commit finances to flight training with the hope of a job.
Another unknown is the popularity with airlines selecting MPL candidates over fATPL's. The new license is growing in popularity across the world and as time goes on.
Instructing is certainly a good route to consolidate experience and understanding that does not require a CPL now so is an option to do alongside you're "day job" (since it will not pay the bills/allow you to save).
There's a lot of info on the forum so the risks are something you need to weigh up and decide how strong you're motivation is.
One thing for sure if you decide to go ahead with it all, be prepared to move abroad for certainly the first job.