To blend these comments together: why are "we" supposed to get the first commitment and/or seeing commitments rolling in consistently?
Lots of factors at play:
(1) college head coach and coaching staffs have their own style. Patty Fitz prefers the earlier, the better. When things were rolling up in Evanston, he would have a week every year in April or May where Northwestern would be ranked in the top five for national recruiting rankings. About 15 years ago, Mack Brown would get 7+ commitments on the first day you could officially offer juniors (looked it up on Rivals, he had nine commitments two days into the offer period for the 2010 class). On the opposite end was someone like Lovie (well documented on here), coaches at elite programs (they can wait on making offers knowing they can offer a four-star recruit late in the process and still win the recruitment), and coaches on the hot seat (need to hope for better results early in the season so they can take that message into homes).
(2) some coaching staffs, especially at non-elite programs, want a bellwether recruit to kick off their class. Whether true or not, there's a belief that a higher ranked recruit builds buzz, they can act as a bonafide recruiter of others, and can create an anchor effect to ward off others from defecting to another program. This initial recruit also may not be the highest ranked, but has some degree of moxie or geographical-political benefit based on their location (i.e., let's get an in-state recruit first!), or both.
(3) Illinois just had their best season in years. Does that mean more recruits are willing to consider your program? visit? post social media propaganda? Maybe Illinois wants to be in bigger recruitment battles this year and, therefore, is going to pump the brakes on recruits they would have instantly taken last year but now view as solid plan B options. This stretches things out as the staff hopes to snag a couple recruits they wouldn't have been able to secure in past years. Maybe you think your season could be rocky due to roster turnover (Indiana) or a grueling upcoming schedule (Minnesota), so you'd prefer locking in those commitments now and spending your energy later trying to hold onto them. These decisions can include PR, confidence, and game theory considerations.
(4) Newer coaching staffs seem to want to completely blow out their recruiting PR earlier in the offseason (February and March), while completely focusing on their current roster through March and April. Strategy here is to build buzz with the new coaching staff (Rhule and his staff visited every Nebraska high school early on, if I'm remembering correctly. Bielema did something similar), followed by assessing how many players you plan on culling from the roster in the Spring before balancing your plans on the transfer portal and fall recruitment.
(5) Social media! I mentioned Mack Brown getting a gazillion recruits on day 1 at Texas. That would never happen now. Every recruit wants that time to bask in the attention and positivity. Websites like 247 want to build content on each commitment to get the clicks. The entire industry is incentivized on spreading things out.
There are many others that could be mentioned (an in-state or conference rival is on the ropes, so you want to recruit hard in their traditional areas/coaching turnover/transfer attrition), but you get the idea that everyone program has their own style and yearly choices on how to build their class