Me and Mrs V got our first wills done with a solicitor when I was 28. Important because we were not married.
24 years later after we were married, we had to make new wills, as the marriage negated the previous ones.
I would not advise appointing a solicitor as executor at the point of making the will. I/we have appointed siblings. The executor can then appoint a solicitor of choosing to take over as executor, all those years down the line, when those firms might have changed, in order to make a good choice. Be aware that the fee for executorship will most likely be based on a % of the estate. That % increases with the size of the estate. Small estate - small percentage charge. Large estate - large percentage charge. The charge is deducted from the estate.
So whether the executor tries to do it themselves or appoint a solicitor - well - you won't be around to see it!
Our siblings will be most likely to appoint a solicitor - I reckon. If we outlive them all, we will have to appoint new executors.
When my mum passed away, I became sole executor (even though I have two older brothers) and got it all done with 0% charge. I was "the man for the job" as far as my bros were concerned and the saving I made on solicitor's fees was considerable.
It just takes a lot of reading and understanding of what needs to be done and then a whole raft of form filling and paperwork then checking and double checking everything. There are IHT forms to fill in even if the estate will not be subject to any IHT. If there had been IHT to pay, then that might have tipped me over into deciding to appoint a solicitor for peace of mind.
HMRC have a free help line if you need clarification about what goes on each form. I phoned once and found this facility to be excellent.
There is loads of free info about obtaining probate and being an executor. Much easier to appoint a solicitor, however, if you don't want the responsibility and hassle.