I've worked solo for many years. I would never consider a job that takes 80 hours for leaf cleanup. That may be a very good time for a solo, I don't know.
However, it does not matter. I have 40 other customers who need attention too. Having a very large job that takes so much time is very hard to manage, while yet keeping up with other customers as well. In fact, I really don't like to have jobs that take more than 1 day. Quickly, my schedule for other customers starts to get too skewed. The 1 day is about the maximum granule size of time I want to devote to one customer. Frankly, I would like to have one customer require 80 hours in terms of work time, travel, etc. But, trying to keep the others happy, while devoting such a large block of time to one customer is not how I like to work.
On another front, I would never take these jobs because too much financial stability is packed into one place. When one customer starts to take near 10% of the sales, then the granule is probably too large. I only have a couple that are around 5%. I would rather have my work spread over many places, lest one large job cancel out, or otherwise leave my customer base, the loss is too much In other words, "Too many eggs in one basket."