Hmm tricky one. 
I'm a cm and currently having a break for family reasons.
It has it's pros and cons like any job....
Pro: at home with own dc. Con: dc share home, toys, mum's attention.
Pro: no childcare fees. Con: Your own kids count in your ratios so less earnings.
Pro: Own boss. Con: Everything is on you. Everything.
Admin .... contracts, child record forms, accident forms, registers, risk assessments, accounts, invoicing, policies and procedures, learning and development file for each child, planning, daily diaries, 2 yr check for HV, GDPR and ICO complaint, responding to parents contacting you. If you get into a routine it's not too bad.
Other things to think about
Your house having a lot more wear and tear on it, usually by kids whose families may have a different level of respect for people's homes and belongings.
Parents knowingly sending sick kids in and then you having to close when it inevitably spreads to your or your dcs and losing your income for closure period.
Some kids like having mindees round to play at their house, some really struggle with it.
Managing challenging behaviour.
Parents trying to drop off early, pick up late, pay late or not at all. You need to be able to be firm but fair and keep to your policies. If you're a kind caring person not used to standing up for yourself this can be hard.
Childcare fees vary depending on area so your potential income can vary hugely depending on where you live. This is worth checking and then doing the sums of what you would earn IF you were full and BEFORE you take all your expenses off. Then take your expenses off and see your actual potential profit, in my area it's not a happy number!