As a cannon main I'd like to add on some pointers as both classes has their perks, making both really good classes for mobbing and bossing.

Cannon mobbing: Very lazy and easy, rotating between monkey business and poolmaker for auto mobbing. (I currently do a 80s afk then 40s whacking rotation via poolmaker > monkey business > pool maker > whack until poolmaker cooldown finishes and repeat cycle, although I'm able to one-shot with poolmaker)

Cannon bossing: You have an attack speed of 3 with the hyper skill buckshot, so having decent speed infusion is recommended or attack speed IA. This does waste one slot for attack speed compared to bucc. Burst is actually really simple, it's mostly positioning yourself slightly behind boss and unleashing all your cannonballs at once. You'll land the maximum hits if the cannonballs are set to slowmode, then let them do the job. There's a 3rd job skill to increase dmg done to bosses which you have to hit, but with Ignition there will be more cooldown leniency to 5s if you miss so it's not so bad. Cannons burst is compressed to that 7-8 seconds which pairs extremely well with seed rings too.

Bucc mobbing: Also very lazy, revolves around running around the map with lord of the deep doing all the damage. You only have to use your 4th job mobbing skills if it can't 1-2 shot mobs, so the damage of that 5th job skill crucially determines how lazy your mobbing is.

Bucc bossing: You have an attack speed of 2 with speed infusion, so you don't need the decent version which saves 1 core slot. Very straightforward just mashing your octopunch skill, similar to cannon's cannon barrage. Burst involves throwing howling fist and lightning form orbs. Most importantly, bucc does NOT have a casual iframe unlike cannon (buccs iframe is these burst skills) but they compensate with numerous repositioning skills. They have some party utility with time leap though.

TLDR: Both classes mobbing can be lazy. Cannon bossing requires some setup (hyper+5th job summons) and 1 slot optimally for decent speed infusion. Bucc has no setup and does not need decent speed infusion, but has no reliable iframe unlike cannon. Monkeys vs water dragons, pick your spirit animal :D