For modular in the UK you’re looking at £65kish if completed in minimum hours with no exam resits, no flying test resits, no medical investigations and that’s just for PPL CPL ME/IR APS MCC without a type rating which is currently around €30k with Ryanair.
You then have to factor in general day to day living costs on top. Living with parents for free is not an option everyone has.
Right now in the UK to complete modular training over 3 years you will be burning through £2000 per month minimum in training costs.
Loans and credit cards? Good luck getting anything decent without a well paid job.
Also - that training makes you a qualified commercial pilot. It does not make you an airline pilot. You may never get an airline job. Any debt is a massive risk if at the end, no airline wants to hire you and you have no other career or qualifications. That’s why people get a degree first. There are thousands of qualified commercial pilots who haven’t been able to get an airline job. Flight schools are full of them teaching PPL for minimum wage.