Monero is good with it’s privacy features. Also, they have some good features inherited from the bytecoin design: smooth emission curve, dynamic blocksize limit. But it has disadvantages anyway:
Transactions size is ten times larger than in bitcoin. If monero has as much txs as in bitcoin its blockchain will growth ten times larger and/or fees will be significally higher;
Lack of infrastructure and real world use. Breaking changes happen often and prevent from integrations in apps;
No active develop or research of Lighning Network/payment channels or other scalling solutions like sharding. Lack of activity makes onchain txs enough. LN cannot be activated in one moment by pushing a button. It needs channel infrastructure, routing network and apps to be created;
ASIC resistance PoW algo makes 51% attack easier. With a block reward reduction to it’s minimum in 2022 attack will be even cheaper;
Benefits for early participation with the emission curve make it harder to get adoption.
Monero is good with it’s privacy features. Also, they have some good features inherited from the bytecoin design: smooth emission curve, dynamic blocksize limit. But it has disadvantages anyway: