Tubes are still a 2.4 Billion dollar industry in the US alone. They are used in many other areas aside from the two listed.
Vacuum tubes have one instrumentation niche in which they are clearly superior: extremely high-impedance measurements. There are semiconductors with very high impedance inputs, JFET and MOSFET transistors, or integrated circuits based on them. However, the semiconductors are not tolerant of high voltage. I own a Keithley 610B electrometer (a hyper-sensitive meter capable of measuring current in the nanoamp range or measuring voltages from sources incapable of producing sufficient current to achieve a reading on most voltmeters). I prefer the 610B to the all-solid-state 610C. The B model is mostly solid-state, but has a nuvistor, a miniature vacuum tube, as the input stage. The FET-input 610C model can be blown by a tiny static charge on the instrument input, but the 610B simply shrugs off such an insult. In this case, a vacuum tube is far more reliable than a transistor!
Another scientific application for vacuum tubes is the ionization gage, a device for measuring high to ultra-high vacuum. This device is basically a plain old diode. The first instinct, upon seeing one of these happily glowing on a vacuum system, is to expect that the filament is going to cause trouble. There is, in fact, an alternative device, the cold cathode gage. Technically the cold cathode gage is still a vacuum tube, an "inverse magnetron," although it uses a small radioactive disk to produce the few electrons needed to get it running, and has no hot cathode. In practice, I've had one old ionization gage, bought used, run trouble-free for years, even tolerating a few boo-boos that caused the vacuum to fail. It has migrated to several experiments, and outlived its original solid-state controller. And, on that same apparatus, a cold cathode gage has needed teardowns for maintenance several times over the same period. The cold cathode gage also stops working at very low pressures, where the rate of ionization is too low to keep it running reliably. The ionization gage's steady flow of electrons keeps it running to far lower pressures.
Vacuum tubes are not yet dead in the radio transmission business, either, especially as you get into microwave power applications. The physics of generating microwaves, especially at extreme frequencies, does not always lend itself to transistors. I already mentioned magnetron tubes, and they continue to have applications other than kitchen appliances. Traveling Wave Tubes (TWTs) and Klystrons are also still in use.
Although silicon controlled rectifiers, thyristors, and Insulated Gate Bipolar Transistors (IGBT's) have replaced tubes in most switching applications, the old thyratron tubes continue to have a niche.
X-ray tubes are essentially high-voltage diodes with anodes made of metals selected for their x-ray emissions. Unless someone comes up with an X-ray version of an LED, this is another niche where the vacuum tube is secure.
The most sensitive light-measurement system known is the Photo-Multiplier Tube, or PMT. These use a photocathode to convert photons to electrons, with very high quantum efficiency. A photon in the visible light range will reliably produce a few electrons with a known probability. Each electron is accelerated toward an intermediate electrode called a "dynode", where it strikes, producing a number of secondaries (the more voltage between dynodes, the more electrons). The dynode string, or "electron multiplier", may have as many as 11 stages. PMT's can be set to such high sensitivity that they can literally count individual photons! Solid state CCD technology is marvelously sensitive, but not yet that good. Used without the photocathode, a bare electron multiplier can be used as a hyper-sensitive electron or ion detector. PMT's and electron multipliers are blazingly fast-responding devices. CCDs work by periodic scanning to determine the amount of discharge they have experienced due to photon impact, and this "integration time" must be fairly long at low light levels.