I have found Family Search (not my only source) very helpful. On my mother's paternal side, I had completed research back several generations. One of the FS contributors, was able to take my research and trace her lineage information back to the 1700's on her grandfather's side. I was able to verify what was offered via my own research the tracing backwards through known people. Very grateful for the major lift on ancestors.
As a long time researcher of my personal family records, I know that this takes a ton of time. I try to get more than one source on most data points (unless it's an obvious correct data point). I haven't had any data lost (I am sorry to hear some have). I do print out every record I find.
Family Search has also found several photos I had no knowledge of. Amazing!
I have been blesseed with great support from Family Search.
I do recommend family geneaology researchers use more than one source for breakthroughs in your research. I have even found information in area libraries with genealogy centers: 1) one library had a book on Polish immigration records. It led me to a traditional spelling of a Polish great grandfather's name (Josef vs Joseph) and another data point which led to a link back to Europe; 2) in another local rural library, I discovered little index boxes with obituaries attached. I was delighted to find the obituary and burial location of my paternal grandmothers father. 3) One of my aunts went to a Wisconsin library where she was able to resolve a question on her mom's birth year, finding a legal birth record which she shared with me. I've also gone to county offices for records as well as out of state offices.
I'm afraid today we rely too heavily on online resources. Even after decades now of researching, I'm still learning something new all the time. Good luck to all!