His thinking is common and in most situations reasonable. But you haven't told us enough for me to form an opinion on whether his thinking is reasonable for your situation and the two parts of it may not be reasonable/unreasonable together: "research is a waste of time for a retail investor", "a retail investor should just buy ETFs".
I would make a stronger case for the first one than for the second. As a retail investor, you will get information that is late and incomplete compared to the information many professionals can get. Professionals don't have an overall track record for doing well with the results of their research. Why would you expect to do well with the results of your research? I don't mean to imply there can't be a positive answer to that question, just that research by a retail investor is inherently starting from a disadvantaged enough position that you need some special reason to believe you will overcome that disadvantage.

For the small retail investor, ETFs have lower risk, usually lower overhead and nearly as good averaged expected return as random (uninformed) investing in individual stocks. If you factor in typical emotion driven mistakes by retail investors, then ETFs have better expected return (in addition to lower overhead and lower risk).

But it doesn't take too very large a portfolio before the overhead difference is reversed, and the risk difference reduced, and tax flexibility advantages of a stock portfolio (as opposed to funds) become significant. So even completely uninformed (zero research) stocks can be a better choice than ETFs. Whether I am talking about $40K invested or $200K before those factors become dominant is a gray area. Certainly I am not talking about reasons someone investing $10K should select stocks over ETFs.