The surface-level message is that you do not need to follow your ideas of redemption to be redeemed: Jakub did not need to redeem himself and his father's name through a great act of public civil service; he was redeemed through the love of his wife.

Hanuš needed to teach him this, and his wisdom is in the "how" rather than the "what" - while he explains to Jakub or tries to get him to see his psychological conflict regarding his wife and his work, it's not until Jakub learns to be different through physically living with Hanuš. Physically, Hanuš is remarkably dissimilar from humans in certain ways (he's literally a giant spider) - and yet he is exceedingly gentle, curious, and enjoys the same simple pleasures we do (the food, the machine noise).

If you watch this really studying how Adam Sandler's physicality changes, you can see there is a really great shift in how he literally "handles" reality.

There's a lot of poetry you could get into when you think of this movie as a fantasy (rather than science fiction) and so Hanuš as a personification of Jakub's shadow side: literally a giant "nasty" who shows him the way to living a better life. I really appreciate this post, because I'd thought of some things that I'd liked about this movie but hadn't been forced into writing them out. Cheers!