It bears really thinking through the alternative:

So we're going to have some engineers specify suitable digital replacements given the process/environment/safety requirements. We'll procure those (noting that an industrial digital pressure transducer can easily push up towards $10k), schedule a plant shutdown (how much does that cost?), then pay a pipefitter/boilermaker to replace the old gauges with new pressure transmitters (do you need a hot work permit for that? Did you get your engineer to sign that off?). Then, your controls sparky has to find a way to route a drop back to your marshalling cabinet for connection into your fieldbus/HART/modbus/whatever network (do you have one of those?) so that your SCADA system can talk to it (do you have one of those?).

Obviously it's not really an apples-to-apples comparison, but I think the costs involved with making "simple" changes in industrial settings are easy to wildly underestimate.

I can see many cases where installing an IoT camera will be more reliable and less costly than, "shut down equipment to unplug this analog instrument, hook up a digital one, calibrate it, then restart the equipment".

If it ain't broke don't fix it — pointing a cheap camera at it with some cloud compute will suffice.