when operating , crt anode voltages are around 20kv for 19'" and under and up to 31kv on the 25"+.
on some chassis, voltage remains long after power is removed.
the reason to discharge should be evident . do you REALLY want to come in contact with several thousand volts ?
think of the worst static charge you have ever had multiply by 10.
its a safety/handling precaution . if u get in the habit of discharging 1st , it will reduce the nasty surprises !
i usually connect the gnd braid to the anode button if its gonna set awhile and /or discharge when ever working around the anode .
been workin on tvs for many years , and still get bit once in awhile.
fyi, it takes approx 10kv to jump an air gap of 1". (granted , this value WILL vary with humidity, etc...)
qrz