It is fascinating to watch how plants reseed; where they germinate. Reseeding annuals give a nice burst of long lasting color. I tend to prefer the bee attractants.
Annual larkspur, borage, even the biennial common mullein (shown below), attracts lots of insects and an occasional woodpecker on the hunt for those insects.
The common mullein can grow very tall and their flower spikes can take on weird twisted shapes. It is also super drought tolerant. This adds a structural element to the landscape, albeit a strange one.
There is a reason I will no longer let them reseed and neither should you. They have about 100,000 babies and can readily overrun meadows and open woodlands.

A common mullein (Verbascum thapsus) stalk from 2016 becomes a structural element, albeit a strange one. Also, annual larkspur; pink, white, and purple, chives, and culinary sage. PHOTO CREDIT: Susan Buffler
I love to see how seedlings move around year to year. I love manipulating them for different effects; pulling out the excess and keeping seedlings where they might look nice and fill in some gaps.
A different planting design every year where there is no parent plant hogging the scene.
I like things a little messy.
Most people I run into want their gardens to stay the same, year to year, frozen in time and space. That is quite an interesting phenomenon and of course mostly impossible.
Are they unable to tolerate change? Unable to tolerate impermanence?