There are many different amplifier designs.
Some have LC resonant on the collector. This needs the trimmer. The gain of this amplifier is high at the resonant frequency and low at other frequencies. It is important to have low gain at 2x, 3x 4x. And low gain at DC.
Some amplifiers have only the inductor on the collector. This is a wide band amplifier. It is easy because there is no adjustment. It is not high quality because it amplifies harmonics. It is not good to transmit on many frequencies. If you are transmitting 10mW at 100mhz then no cares that you are transmitting 2mW at 200mhz. In a radio transmitter that is transmitting 100kW you can not transmit 20kW at 200mhz and 1kW at 300mhz and 2kw at 400mhz etc.