Apart from noise, the main issue is cost. Geared drive to the camshafts obviously takes more precision parts, more time to assemble and a more complex engine block. Keeping it quiet also requires more complexity ( Honda (say) with spring loaded gears ).
Exactly this. Honda's motorbike division dropped a major clanger in the 1980s when it introduced a range of V4 engines, led by the VF750. Unfortunately, the engines were not tested for long enough in real-world conditions.
Owners quickly found that the camchain tensioning system was inadequate and the cams themselves wore out, often within a year of purchase. Both problems would kill engines. Several updated parts were specified but they were only partial fixes. The warranty costs were crippling in the critical US, UK and German markets.
Honda redesigned the engine and gave it gear-driven camshafts, and that version was ultra-reliable and largely saved the reputation of the company's bike division. But it later reverted to chain-driven cams again, for cost reasons
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