I have begun doing a young adult diary-style novel set in the 1980s, the decade in which I grew up. Such works are called epistolary novels, the subject of one of the reading challenges I have been doing this year. I've read over 25 such books to date this year and have some at home I plan to read.
Such books have traditionally been in the form of letters, or a dairy, but have come to include emails and text messages to go with today's trends. However, I have found myself less compelled to write something set in current times, hence the reason I chose the 1980s. I also would like to have kids today see how those my age did things when we were kids their age.
This graph from this link shows a rise in the popularity of the epistolary novel over different periods:
How many of you have considered writing this in style?