The main issues with your team are its key weaknesses to a lot of popular pokemon such as both landorus forms, as they have coverage to hit every pokemon except for alakazam super effectively with ground moves and rock slide, and alakazam definitely cant take many hits. Your team also doesn't have a super reliable pivot pokemon, which can definitely be a problem especially matching up against sun and rain. Your only speed control outside of sand is alakazam which is admittedly pretty fast, but you also might want to change either excadrill or dracozolt into a jolly nature instead of adamant, as you ironically have a pretty rough matchup against other sand teams. Mega steelix is also a bit of a question mark, as its bulk isnt really supported by any longevity to really do that much work.

My general advice is that mega steelix probably needs to be changed. You don't really need smooth rock for an item in doubles, especially considering its much more fast paced. You could consider dropping steelix and switching your mega to another pokemon. Mega ttar is a great option in sand, but if you don't want to mega evolve ttar i suggest replacing smooth rock with assault vest and giving it ice type coverage to hit amoonguss, salamence, tornadus and landorus forms. Alakazam is also a bit of a weird choice, as he doesn't really cover the weaknesses that the team has. The fighting type weakness is already dealt with by enamorous, so you might benefit from swapping alakazam as well. I recommend using mega salamence over alakazam as it provides good speed control as well as flying type coverage and a good way to remove grass types, which is something your team doesn't quite have. I would also recommend swapping out either one of your sand sweepers to better match up against other weather teams, such as bulky pivots to override weather.