I would say it all depends what your ambitious are. Instructing at local club or Airlines.
When I was 40 I had already has my PPL for long time, so I did not start from Zero, but I had not flown for almost 20 years or more.
I did modular, and was 42 when I finished the courses. 12 months later I got my first Airline job, and it was a lot of luck getting that first job.
Hard work. It was based in Europe, so would not work for most UK pilots today, with a young family, and commuting by air 3 hours to get to "home base" I used to have 2 full days at home, and 8 days of work and commuting either to work or home. But if you choose to go this way, you can't be picky and you should be aware of the pitfalls if you decide to invest +£100K into this career at a late time in your life.
It's hard on your private / personal life and health, when you start commuting, as you miss almost everything of importance and have very little say over your own life the first 4 - 5 years, it cost me a marriage (divorce) and the ensuing battles that comes with this (phycological stress which almost cost me my job/ career) This can manifest itself through your Sim checks, medicals and mental health with all the stress going on around in your life. Spending 2 days at home within a 10 day period, definitely did not improve family life, although for me personally there were other reasons for the divorce then the commuting / flying job, but it certainly was a factor.
Also be aware of even if you have a Class 1 medical, there are many things completely beyond our control when we get older, that suddenly happens with little or no notice. Issues with eye sight due to age, abnormal ECG readings which will cost a small fortune to have diagnosed, unhealthy lifestyle (food, drink etc) and work life (fatigue).
There are so many "traps" during this career if you manage to get into it, that can make you loose your job and your +£100K investment in training.
I was "lucky" and commuted only for 2 years, before I managed to get a job back in the UK. Instead of commuting 3 hours by air, I was now commuting only 4 (2+2) hours by car or train every day, but at least most days I was home with my family.
The initial contract for the first 4 years also back in the UK was not the greatest, depending on your lifestyle it might be big changes in your life and spending habits, besides if you are commuting the extra costs of these too adds up, both financially and with fatigue.
However during the whole time since I started, I made myself "small goals", and slowly over time I have ended up closer to home, better TC's and finally I got my move to LHS, 10 years after my first job in the industry, and delayed by 2.5 years due to Covid, which was another massive scare for the industry. The loss of Covid due to my age vs example pensions, has cost me a lot, but at least I managed to keep my job and get my upgrade as soon as life came back to normal.
But during the journey there have been many obstacles on the way, things that are beyond our control, things that can risk the economical security and safety of your family. So yes there is a bitter sweet happy ending, and overall I have no regrets, but this is the reality and it took me 10 years to get where I wanted, and the fear is that you can loose anytime for a dodgy ECG reading.
As an "older", we carry a lot more luggage in our lives, then someone in their early 20's or even early 30's.