I'm writing an answer to expand on what @ceejayoz wrote in a comment on your question.
Is this a trend in the industry? Are all the trustworthy issuers (read: large, well-known companies, like BofA) walking away from cards that provide this set of features?
Ultimately, yes - this is a trend. And there are a few reasons behind it, but basically it's because there are solutions available now which do a better job at the actual function you're trying to fulfill.
Historically, consumers generated and used single-use card numbers with fixed (low) limits as a way to protect their real credit card number from getting stolen during a transaction, and/or as a way to "limit" what a merchant could (potentially fraudulently) take from their account.
However, these virtual credit card numbers are an imperfect solution. There's essentially nothing stopping someone from stealing it and using it before the merchant can, once you've generated it: there's still a portion of the process that's vulnerable, because it's being done by users through user interfaces. That means there's a (fail-able) human element involved.
Further, virtual credit cards with artificially low limits could cause issues with merchants who may have legitimate reasons to charge you more or otherwise to alter the transaction after the fact.
Luckily, there are better solutions these days: most notably, electronic wallets (i.e. Apple Pay or Google Pay) which essentially do a better, automatic version of the same concept, but without the same issues. Essentially, when you use your card via an electronic wallet, the merchant gets a token to use for the transaction, so your actual card number is protected. That token is basically useless outside the scope it was created for, so it's more secure than a single-use card number. Also, since it's created and used automatically, and never directly available at the user interface, it's harder to steal (no one can shoulder-surf and write it down). Further, merchants get more flexibility to manage the transaction than they had with a single use card number, so it avoids the potential issues for merchants, as well.
These changes have lead to the trend you're seeing - card issuers are phasing out the single-use-card function because - for the most part - all parties involved (merchant, consumer, bank(s)) are better off by not using it any more, and using electronic wallets instead.