I don't think it's necessary for you to start off thinking that you should give your novel an underlying meaning. In most cases, even if you don't mean it to, the way your plot unfolds, the way your characters act, and the ending you give your book will ultimately say something about how you see the world. Why is your villain a villain? Is it because she is trying to make money and get ahead at any cost? Because she is trying to undo something of society that she sees as a misstep? Because she needs affirmation to keep her self-esteem above water? What is the ideal state of affairs as far as your novel has it? One of minimal government where hardworking individuals can succeed? One of collectivised society where vulnerable people are protected as much as possible? One where people are pushed to achieve the most that they can? It doesn't matter whether your novel has an underlying message by choice - once you decide on what constitutes a protagonist and antagonist, what counts as a happy or sad ending and why, your book has an underlying meaning by default.
As other answers mentioned, no book really needs to have a deeper meaning. The vast majority of books really don't have an inherent "meaning" beyond whatever the reader ascribes to it based on their own perspective. But, in my opinion, whether or not you decide to imbue your novel with deeper meaning depends on your intention as an author. Do you intend for this novel to remain relevant to the reader after they close it? And don't say "I still remember what happens in a book after I'm done and I still like it!", I mean is is relevant in the sense that you would spend a lot of time thinking about it and revisiting it after reading it and you'd come away with a new idea about something? If so, your best bet is to layer your novel and make it capable of sustaining meaningful analysis on the reader's part. It's not particularly difficult and if you're already practicing good writing/editing (careful word choice, pacing, style) that makes it easier. The main thing one needs to worry about when they decide to give their novel a meaning is consistency. Whatever theme you've selected has to jive with what your characters are doing, thinking, feeling, and saying and if not that should be intentional (and part of the analysis) and not the result of bad planning.
And you could say that entertaining the reader is your way of getting them to stick around long enough to get the message.
I dare say that for me personally the underlying meaning is the last thing I think of for anything i've written. and things can still turn out great without it as well, but if you find an underlying meaning appearing, then allow it to grow but not in a "look at me" kind of way
Books can be more than just deep - they can be - deep or entertaining or educational - or all three. It's not necessary that you need a deep layer so long as your book is entertaining.
Whether or not your book should have an underlying meaning depends on the type of book your writing. However, I personally love any story that does include an underlying meaning. While it's not necessary for a book to have one to still be good; I know having a good underlying message can make your story a lot more memorable in the long run. It doesn't need to be a complicated meaning it for it to work well either. Typically if you want to have an underlying meaning in your story though you'll have to have the story revolve around it to work, so unless the point of your story is for it to have an underlying message you shouldn't go for it. It'll just hold you back in the long run.
For me, deeper meanings in literature are like add-ons or DLC. Metaphors and symbolism won't stand on their own, but they add an extra layer to your existing story. It's what brings readers back to read your stuff multiple times, and that's what builds fandoms.