Should I bother going for level 1/2/3 raids and waste my raid pass?

Free Passes are only wasted when you don't use them. Soloing tier 3s can give more rewards than doing a higher tier raids with larger groups

Depends what are your priorities and you consider waste. Soloable raids are often more convenient and they have featured new pokemon like Shinx and Buizel recently, which can be quite valuable to some players. If I can get 9 candy from pinap catch+trade for a new dex entry just by stopping at a gym for 2 minutes (since I can start walking again immediately after the raid starts), it can be a much better deal than waiting around for a group for Tina for an average of 3-4 rare candy and maybe a TM.

Do whatever fits your schedule and gives the rewards you value the most. If you mostly need CTM and RC, stick to legendary raids and solo tier 3 as backup.

It depends on the pokemon. It happens too often that some pokemon in low raid tiers are more useful than the current T5.

If you don't have 6 Machamps with good IV - go&get all you can!
with one good Machamp, it's possible to Solo Sneasel with only 1 mon...
With enough, you can be part of a Tyrannitar Duo.
Tyrannitar (&Weavile) can be part of many Teams.
Also save your Machamps for trading - may get lucky...

If it's something you don't have (e.g. shinx or buizel) or something meta relevant (e.g. Ttar, machamp) or something that can evolve to meta relevant (e.g. piloswine, dratini, etc... Many in this group although few in rotation) then I don't think it's a waste - especially as you get later in the day and aren't sure you'll find a legendary to use your free pass on.

All I do is solo raids. I live in a small community that actually have active raiders however they are extremely toxic. They will allow you to raid with them if you show up but to be part of the Discord you have to go through a hazing period. At the end of the period the last thing you have to do is be paddled in the butt while you scream your favorite Pokemon name while other members record you. So I just stick to solo raids....

If you find yourself not using the free pass due to waiting for a T5 to happen then yes, absolutely. As user Ianstul above put it, the free pass is only wasted if it goes unused.

There's no right answer.

I do Shinx, Alolan Exeggutor and Kirlia raids because they lead to useful Pokémon in the future, so they are essentially free Candies and fairly powerful Pokémon (67%+), and even Weather Boosted are easy to beat solo.

I do Shinx, Snorunt and Mawlie raids to get potential Shiny's.

I will be doing Buziel because it appears to only be found in Raids. (I might be wrong about that)

I do Alolan Exeggutor and Dratini raids when I have a "Catch a Dragon-type Pokémon" quest.

I do Machamp raids when I'm helping a lower-level player get a Weather Boosted Machamp (which is often 2+ levels higher than they can technically catch).

Most days, though, due to how stupidly Niantic spawns raids, I don't do a single raid. Most people I raid with don't want to do Giratina any more, most people won't do a Level 4 that isn't a Ttar, and Giratina are the most common raid in my area. There are many days where I would be willing to do ANY Level 3 or lower raid - even Granbull or Shuppet - if one spawned nearby. But nope - Giratina.

So it all depends on what you want to do. I try to spend that raid pass daily if I can, without waiting for Level 4+ raids. If you want to wait for Level 4+ raids, that's perfectly viable as well.

Yes, as was said above and echoed, free passes are only wasted when not used. They are, after all, free.

My feeling, as a free player, is that when there's a really strong tier 5 raid boss, I try to dedicate all my free passes to that. Rayquaza qualified for that, Giratina and the Regis did not. So if Palkia comes out after Nov 20, I'll be using almost all my free passes on that. Right now, I do a few Giratina raids, as well as Shinx, Kirlia, Togetic, and I'd do Piloswine, Magneton, or Rhydon if they were around. Buisel as well, although not as enthused about that one.

If you're all about getting the most RC and TMs from raids, stick to the highest level ones you can. If you want a good spread of strong pokemon to raid and battle with, do the ones that help that goal the most.

Really the question should be..... Should I bother wasting a pass on Giratina when I could be raiding Togeric, Tyranitar, Machamp, Sneasel, or Kirlia actual useful Pokémon?

Current crop of tier 3 are boring and/or not useful. I have 96% and 98% Machamps that I’ve never powered up because I have plenty of 89% weather boosted ones at level 35. I can’t see what I can get out of this crop anymore.

Yew. If you genuinely want gym XP you should even spend premiums if it's a quality or useful mon.