Do tubes have to be matched?

That mainly depends on what the tubes are intended to be used for:

Power tubes

Power tubes should be matched if they are:

operated in a push-pull amplifier, so that the transformer does not go into saturation and hum as well as distortion are avoided; important parameter: anode current

used in stereo or multi-channel operation, in order to avoid volume differences between the channels; important parameter: transconductance

Small-signal tubes and double triodes

These should be matched in:

phono stages absolutely, because tube preamplifiers usually have little negative feedback and otherwise channel imbalances can easily occur; the voice moves out of the center and spatial imaging suffers

line preamplifiers and stereo tube amplifiers, in order to avoid channel imbalances

In guitar amplifiers, input tubes do not have to be matched, because they usually work cascaded and are built as single-channel circuits.

In musician amplifiers, matching can be useful in the phase splitter or phase inverter in order to drive the power tubes evenly. This improves headroom and is especially recommended for clean sounds.

Special cases

In tube radios, matching is usually not required.

In amateur radio power amplifiers, matching is usually recommended.