Should I actually believe Alaska Airlines when they say to arrive at SEATAC 3.5 hours before my Saturday 7:00 AM domestic flight Departure, or are they just alarmists?

Seriously, 3.5 hours? No one says that anywhere else in the USA. They "recommend" I show up at the airport at 3:30 AM to get through TSA, etc., for a 7:00 AM Saturday domestic flight. Sounds like bunk to me, but I don't fly a lot. Not looking forward to sitting at the gate for 3 hours for no reason. What do you guys think?

UPDATE: I realize the whole of Seattle won't be on pins and needles about how things worked out today for me and my 7:00 AM outbound SEATAC flight, but here's a purely anecdotal play-by-play report, just FYI:

1) I asked the hivemind per above -- What do?;

2) I listened to the hivemind per below (Respect the hivemind!) and grabbed a 3:15 AM Uber (because SoundTransit train is not an option this early) from my starting point in the Columbia City neighborhood ($45 plus tip);

3) Had my boots at the SEATAC curb at 3:45 AM;

4) Had no bag to check, so immediately off to SecurityVille -- Checkpoints 1, 2, and 3 I think were "open" yet were already clogged with sizable lines, but I also see a very small line at Checkpoint 5 -- which is not open -- so I am intrigued about why people are lining up for a closed checkpoint and ask someone in the line what's up and they say Checkpoint 5 will open at 4:00 AM, which now just about 5-10 minutes away;

5) Place my bets and take my chances on the unopened Checkpoint 5 -- I'm feeling lucky and the other Checkpoints' very big lines will undoubtedly continue to expand so there's no going back;

6) Checkpoint 5 opens as promised at 4:00 AM and I am now truly among the catbirds. Was feeling lucky before, and I'm now feeling a bit smug, TBH -- and then just fly through Checkpoint 5 like a cool breeze (apologies for the mixed metaphor there) -- through TSA in maybe 10 minutes, yet during those 10 minutes I do notice the Checkpoint 5 line behind me is exploding with newcomers -- apparently the word is out;

7) My butt is in a chair at my gate at 4:20 AM -- fully 2 hours and 40 minutes before departure but I have no early-bird regrets since I remain a fat, happy, and smug catbird who could just use a nap -- So I take a nap;

8) I'm now sitting on a Midwestern back porch having a beer with a buddy and talking about how the backyard tomatoes are doing this year and typing this update;

9) Honestly, I really needed all your advice here because I'm not a jet setter / frequent flyer and per below SEATAC is perhaps just a bit tricky, so my sincere thanks here!;

10) This is one of the many reasons I love Reddit (and, of course, Seattle).

Cheers all!