Analog audio basically became obsolete near the end of the previous century when Detroit, and other world-class automakers, abandoned it for digital techniques to be used in automobile sound systems.
I did not say, and I hope no one thought I implied, that analog (electronics) was obsolete. The real world (except for certain quantum mechanical interactions)
requires interfacing electronics with analog signals. It's just not done (much) anymore with discrete components. Certain vacuum tube power components are still being manufactured and are in use: Magnetrons for RADAR and microwave oven use, klystrons for UHF and microwave transmitters and receivers, TWTs (Traveling Wave Tubes) for microwave power amplifiers, BWOs (Backward Wave Oscillators) for microwave transmitters, water-cooled triode, tetrode, and pentode vacuum tubes when ten kilowatts or more plate power dissipation is required, x-ray tubes in sizes suitable for small dental x-ray machines to very large (and mostly classified) x-ray tubes used to verify the operational condition of our nation's stockpile of nuclear weapons. I've been involved with all of these at one time or another during my career working for defense contractors. Analog is NOT obsolete. Vacuum tubes are NOT obsolete. Analog engineers and technicians are NOT obsolete.
Commercial applications of analog technology may still linger as niche applications, but the heyday of their use has long passed. Have any of you old farts received your digital aural implants yet? Rush Limbaugh may have been the first person to nationally inform the public of the availability of cochlear implants to restore hearing, but there have been other interesting developments in prosthetic research. Research in this area requires familiarity with both analog and digital circuit design and application.
I began my career as an analog experimentalist and hobbyist, sometime around 1952 or 1953 when I started living temporarily with my grandparents. I began reading everything I could find pertaining to electricity and, later, electronics to try to understand all the neat and wonderful things grandfather brought with him to Morristown, Tennessee, after he retired from a career as a deep-coal mining electrician near Welch, West Virginia... motors, transformers, selenium rectifier stacks, Edison cells for miner's lamps, carbide miner's lamps, all manner of "mysterious things" to whet an eight or nine year old's appetite for adventure. And Grandfather let me play with it all, and tried to pass on his knowledge of electricity. Unfortunately, Grandpa knew diddly about AC, so I didn't hear about Tesla until I was in high school.
ICs are fine if you check to see that they are still being made and when you do not buy cheap fakes from China (Ebay, Banggood, AliExpress, Amazon, etc).
@Audioguru is spot-on about the difficulty of obtaining genuine parts from Asia, especially from China, who has the capability, and the will, to reverse-engineer and counterfeit just about anything. This isn't always a disaster: some of the "cloned" parts work as well as or better than the originals. Problem is, there is no way that I know of to determine which ones are "gud enuf" and which ones are a total POS to be avoided at all cost.
Lest your expensive satellite transponder and its electronics fail soon after (or during) launch into orbit, purchase name-branded parts from reliable, vetted, distributors. A money-back guarantee is worthless if the failed part cannot be retrieved for replacement. With China you may get high volume, low cost, or quality control. Pick two. Then read your contract carefully.
