Ultimately people just don’t want you to cycle. This is very much a cultural thing. Anyone cycling past age 15 or so is either poor or dangerously counter cultural. One of the most interesting things about the Netherlands is that is very little bike culture! You don’t see people signalling with messenger bags, cycling caps, bike brand stickers etc. because choosing to cycle is not unusual.
Something that worked comparatively well for me it so shout “I’ll pass on your (left/right)”