I don't believe that's actually true. There are almost always opportunities in the medium term to pick up shares of decent businesses which are undervalued by the market. If anything, there tends to be less of these opportunities in a Bull market than Bear
Lewis were up 70% in 2024 having traded for the last several years well below book value despite consistently being a profitable and dividend paying business. Altron was up over 100% in 2024 finally reaping the rewards of a successful turnaround a couple of years ago. Even a couple of stocks such as Nampak and Stefanutti Stocks seem to have turned a corner somewhat following some difficult years.
I think if you look back over the last 5 or 10 years, you will see that the opportunities have been there despite the state of the economy.