My favorite web based service by far is Google Tools — Gmail, Meet, Drive, etc. I particularly love Google Drive. I have used Drive for team projects in the Army, for classes in college, and for personal as well as business use. The most prominent example of its usefulness was when I was on deployment for 9 months and was able to help my husband run our business by posting photos and documents to the drive. He would send me photos to edit as well as notes about current projects, and I would then process the photos and create spreadsheets and documents to keep track of finances, records, etc.
Google Meet is also a great asset during the pandemic, as several of my classes have used Meet instead of Blackboard since it does have significantly less technical issues than Blackboard. Several of my classes also use Google Drive along with the built in Google Docs, Sheets, and Slides in order to turn in assignments or work on projects collaboratively with other students.
The pros of Google Tools are the user friendliness, overall ease of use, and the ability to collaborate with others. I have not really experienced any cons that I can think of, as all of the programs work well with Microsoft programs (Word, Excel, Powerpoint) that I also use. Zero complaints here!