Ditto to the above.
Many agents choose to join a team because it relieves them of quite a bit of 'paperwork' that they don't enjoy. For instance, a buyer agent for a large team may write a contract for a buyer, then turn it over to the transaction coordinator who does all of the follow-up with the lender, the title company, the inspectors, survey, etc. This frees the buyer agent up to spend more time with more buyers.
Of course the assumption here is that there is a full plate of buyers to be had. And one would assume that an agent busy enough to start hiring buyers agents is doing so because they really do have too many leads and clients too handle. And for a good team, this process works quite well. Unfortunately this is not always the case. I've seen any number of team agents wandering around looking for business... and receiving little or no leads from their team lead.
So if you think joining a team is right for you... research VERY carefully! How many buyer agents are working on the team now? How long have they been with that team? If there's a history of buyers agents coming and going every six months or so... chances are they were promised the world and didn't get it. If on the other hand a team has agents sticking around for years... well, you probably will be in good hands.
Good luck!