I would think of their hardware as cryptographic rather than exclusively currency related: even without cryptocurrencies around, you might need that hardware to operate strong encryption, either on your laptop or as a service. I’m not very clear on what are the next requirement and algorithm coming, but it sounds like a reasonable area to invest in.
If you look at it slightly differently: this is a company who was able to be successful in the cut-throat B2B hardware integration business. Even if some of the key aspects of that hardware might not be relevant, they have demonstrated agility at scale, which is valuable. Every company with the same scale in China has been able to negotiate full pivots repeatedly: maps become platform, search engines conversation agents, integrators turn into high-street brands, etc.
The block reward halves approximately every 4 years, and it's currently halfway through the 12.5 BTC reward period. Based on this schedule there will be a mining reward until the year 2140.
In addition to the block reward, the miner who finds each block also gains a fee from every transaction in that block. Ideally this fee stays low, but it depends on network congestion (and what miners are willing to accept, since they choose the transactions that make it into each block). The transaction fee has already hit the equivalent of $50 per transaction, back in late 2017.
Even with improvements such as batching, segwit, and lightning, there is still likely to be sufficient returns to incentivize miners for the foreseeable future.
If you look at it slightly differently: this is a company who was able to be successful in the cut-throat B2B hardware integration business. Even if some of the key aspects of that hardware might not be relevant, they have demonstrated agility at scale, which is valuable. Every company with the same scale in China has been able to negotiate full pivots repeatedly: maps become platform, search engines conversation agents, integrators turn into high-street brands, etc.