As others have said it depends on where your ancestors are.
I have a paid everything/everywhere subscription to Find my Past UK, I find their search much more accurate than Ancestry, they also have records that other sites don't.
I don't much like their trees and don't use their tree builder.
I also have had an Ancestry subscription for 10 years +, tree building is easy, you do have as you said be very careful about the multitude of unsourced/copied/incorrect trees as possible sources of information.
I have not used other pay sites. Oh except for Scotland's people which is a pay as you go site.
Other free sites I use often are Free UK Genealogy,
https://www.freeukgenealogy.org.uk/
It includes Free Birth, marriage and death records from 1837.
Free British census from 1841. Probably their best records are Free Parish records for baptism, marriage and burial.
Yes there are complaints that their records are not complete for all churches in all areas of Great Britain, it is a volunteer run site and it takes time to transcribe original records, what you will find is more complete information transcribed from the original records. Such as father's occupation, family residence as opposed to just the church location for the event. And it isn't the most intuitive of sites to search, just follow the instructions.
Family Search, free, is good for finding records just be careful of the family trees.
There are many other sources that can be found with a Google search. As an example after many years of looking for records for ancestors from the village of Bunny in Nottinghamshire, I googled Bunny Village Nottinghamshire history and ended up on the village website which has many records transcribed by the local historical society
In Great Britain don't forget the many local Parish Clerks websites. Yes they are transcribed records, but usually very good.
Another option which is technically a paid site is British Genealogy, it is run by professional genealogists, yes for a fee they will research your family history.
They do have a completely free advice forum, you can ask almost any sort of questions about where to find records. They will not do unpaid family research but will look up records and offer valuable advice about where to look.
The Advice forum requires a free sign up, and do not expect a speedy response, they do have paid work to do, I have always received excellent advice and information.
https://www.british-genealogy.com/forum/
Archive.org has hundreds of Parish records for uncountable places and other local histories. Take time to figure out how the search works.
In general I like Ancestry for building trees, but I love WT for accuracy and member support.