My experience with all the different jpeg compression applications and online services has been that they all do about the same thing when they are ”set” at the same level of compression.
Your lightroom is set to 30%, and some products like squash, tiny jpeg, and others are set much higher (70% or more) by default. It gives people the impression that they have some ”better” compression going on. When in reality they simply ”turn-up” the compression out of the box.
Of course, when you turn up the compression you also turn up the loss of quality.
Image compression is a balancing act, quality vs file size (page speed).
ImageOptim Offers ”lossless” compression, and that’s achieved by simply stripping the metadata from the image. I don’t know lightroom, but it may very well offer a similar option.
If you turn on lossy compression, which is where you get the most benefit then they all pretty much work the same. Compression is compression, there’s no magic that one product offers over the other when set at the same level.
It’s a matter of workflow and what works best for you. For example ImageOptim will only rewrite the files in place. I can’t stand that way of working. I often want to keep trying different compression settings to try and balance quality vs file size. With an app like ImageOptim, I’d be constantly re-copying the originals back.