Engineering has bombs and arcane bomb is pretty badass, but alchemy does get alchemists stone at some point which will increase the healing/mana you gain from drinking healing/mana potions. That might seem lame, but if you throw a bomb and miss it is just wasted. Meanwhile it’s harder to mess up just straight up healing/mana yourself more.
Though that does take a trinket slot.
It’s unfortunate, but there aren’t a TON of special things for other professions, but there is Phytoblade for herbalism (which will quickly lose it’s value).
Some engineering only items share cooldowns with other categories of items. Like health stones I believe share a CD with minor/major recombobulator. So as a self use heal, a health stone would just be straight up better. The recombobulater would only have the advantage of added dispel flexibility on allies, but it ALSO requires a trinket slot AND has charges. I’m not 100% sure about what bombs share a CD with, but if you are curious you can check sites and look for ‘shared cooldowns’ to find out replacements.
Engineering is awesome, but 100% not required. Some people have just developed a limp without it. Highly recommend looking both professions up and deciding for yourself which sounds more enjoyable.