Your question of,
Why would I, as a consumer, choose X over Y?
is really only half the puzzle here. As basically stated in quid's answer, There may not be a good reason for you to choose X over Y. But, that may be the desired conclusion for you to reach based on deliberate, artificial pricing conditions the bank has created. In other words, you also need to consider,
why would the bank price X and Y in this way?
I think this is worth considering as a slight frame-challenge to your question because sometimes, banks do not price products based solely on textbook-standard approaches. As consumers, we expect that a product is priced based on risk and liquidity - more risk and less liquidity should mean a higher rate, so - unless there's an expectation of significant economic changes in the near future, you're right - we would expect a CD to have a higher interest rate, but because it doesn't, most people would probably choose the savings account. The answer to your question is "you wouldn't open the low rate CD right now."
Of course, none of us here likely know the exact reason why this bank is currently pricing things this way, but the common reasons would include:
They may be trying to get their balance sheet to a certain goal in certain products. A bank's own deposit strategy will dictate a level of risk and liquidity they want in their consumer's deposit accounts. From a certain perspective, a consumer opening a deposit account can be thought of as the bank taking out a loan from that person. The bank will want to maintain a certain mix of "loans" from consumers - so, in essence, they will sometimes deviate from standard pricing models to try to capture more dollars in a certain product. This is very common in institutions that serve niche markets (i.e. online-only banks, or credit unions that specialize in a certain market) because consumer behavior in those markets may not reflect a more typical institution's mix of consumers, leaving the institution with an unbalanced mix of deposits.
They may have some promotional strategy based on expected behaviors. Typically, institutions will have a consumer strategy based on capturing consumers and/or retaining consumers. Depending on whether a bank wants to be biased towards "capture" or "retain" at a certain point in time, they may shift their pricing to target those results. Typically, this is done because certain products are associated with certain consumer behaviors. For instance, they may be willing to essentially lose money on the savings account because it's seen as a product that helps retain customers. Or it may be seen as a stepping stone to being able to sell a consumer something else, which actually creates the retention. Often, institutions will have specific product sales goals based on these expectations, which may be targeted at promoting a specific product, or trying to create customers with a specific mix of products.