They can be opened peer to peer, or hop between other channels, similar to dns routing
They are prefunded with a certain quantity of bitcoin that dictates the size of bitcoin that can move in that route at once - although smaller denominations can go through in rapid succession this just means more fees levied
All of this incentivizes a larger channel to be created by a well funded party, which can be coaxed into censoring transactions because they are a payment processor or institutional service. Likely an incumbent such as Visa joining the lightning network as a victim of LN’s own success.
There are some mitigations built in and actively developed. We are 8 years deep into Lightning.
lighting channels are expensive to open and close
as it stands, there already isn't enough block space for “mass adoption” users to all have their own single lightning channel
let alone several
lightning in its ultimate form will always be a hosted solution
and those with the acumen and willingness to pay to open and close channels (or perhaps use the L1 bitcoin) will be a separate class of people