@OneBigHoliday So to simply answer your question from my own personal point of view / experience;
On FI I've been able to SLOWLY (over 3yrs) accumulate a portfolio of players who now regularly return me £1000 per month, I have a balanced portfolio (possibly too diversified) and so believe this will continue for a good while now. I've never had more than £15k of my own money in here & that was to maximise a bonus offer and it was a very stressful time & I quickly got back to what I felt I could ''afford to lose // have tied up for a good amount of time.''
It's given me a love of all the top 5 leagues, I have favourite clubs from each one. I love when the teamsheets come out so I can see which of my players are starting and I love following the matchday PB table and seeing my players do well. I also love waking up to find one of my players has sntached MB with a 11.30pm article :-D
I can now do all that without risking another penny (unlike traditional betting) so that's why I continue to love FI :-)