More often than not, WiFi would fall under a splurge/self-treat for me personally and wouldn't necessarily fall into the planning stage when booking, WiFi considerations or availability would only come after price of fare, convenience of schedule, the airline itself/loyalty program, preinstalled IFE options, or the cost of the WiFi service if applicable. Over this past summer I sampled DY's free intra-Europe Wifi, VX's $18 ViaSat on SFO-DCA on their A321neo, and AS's Free Chat, while in the past I used WN's $8/day WiFi.
Perhaps it had to do with how it wasn't late at night anymore compared to the previous time I used DY's WiFi but it was super-slow and I was never able to upload a picture to social media (whereas I accomplished this on a late-evening DY flight the year prior), and I felt it would've been better off if I'd never even tried using the WiFi for that purpose as it consumed a lot of time for what ended up coming to nothing. I suppose just browsing here and there or using IM apps would've been a better use of it.
Splurged on VX's ViaSat last month partly because AS Free Chat apparently wasn't available (but was on the return) and used the opportunity to browse or update social media and not so much do any work. Anything I'd consider work wouldn't require the necessity of WiFi (any files I need, I could send to Dropbox from my desktop before I leave home and my laptop would sync and download the files at home if not at SFO or any departing airport that has WiFi), and really that flight amounted to gloating to my friends that I was on pretty advanced WiFi that wasn't at all slow that I could do things that'd normally eat too much bandwidth. Another bonus was being able to switch WiFi connectivity devices by entering the transaction email in the web portal on the specific device, so ideally one person could buy a pass for two or more if they were willing to take turns. But no, I wouldn't call this a necessity for me.
AS's Free Chat says it works on Facebook Messenger, Apple iMessage, and WhatsApp, but after using the service I was getting notifications for other apps (such as Discord/Discordapp) and could even browse my social media feeds or send/receive tweets (including one such tweet from VX's twitter in reply to me that other apps and limited browsing was still possible on Free Chat). I suppose it was a bit like DY's WiFi in that uploading files or large files was not supported but it said so upfront rather than falling short of expectations. This combined with the Alaska-licensed free movies that at the time, recently became available on VX flights would probably be the most "economical" option where there's seatback IFE options as well as being able to remain connected.
So in essence, for me WiFi is welcomed but not so much a necessity (at least not as much as in-seat power, the VX flight I used AS free chat had inoperable powerports and they were still the 2007 model screens without the USB ports like the new ones). In some cases I've grown not to expect or rely on WiFi considering, say, how much it'd cost to have available on Norwegian's 787s, as their IFE selection in my opinion more than makes up for it.