I think it is a terrible idea, and so do my late teen/early twenties DD's.
16/17 year olds can obviously be very intelligent and well informed, they can also be completely set in their opinions, bolshy, and have no life experience. They are unlikely to be supporting themselves, or paying tax, and in the main don't live independent lives.
At 16 you can marry, get a job, have kids, rent a house, join the army (and die for your country); but you can’t vote or drink. It’s a stupid set of rules. How is voting more of an adult commitment having a baby or marriage?
Many posters citing the above. However, you can't die for your country. You can marry and have kids, but would that be considered a good decision? You can't rent a house without a guarantor or support from a parent.
Shamima Begum is a great example of double standards. So many people citing her youth and inexperience, and lack of understanding of what she was doing. She was 15/16 in Year 11, and potentially therefore eligible to vote in that year.