If you didn't know riot is currently reworking teemo and it's on the PBE.
Teemo just lost his old passive.
What do i mean by the old invisibility mechanic ?
nvisibility was something simple however it could be op if you didn't used the right objects.
A pink ward...
YOU JUST HAD TO BUY A FUCKING PINK WARD TO SOLVE ALL YOUR ISSUES. (the pink ward could reveal invisible characters in the past).
akali, teemo, shaco, eve, twitch etc. were all strong but the counter was the pink ward.
When riot decided to give free wards for everyone it destroyed the game in a way :
Stealth and ambushs were way more difficult because now the map could be way more easily fully warded. In consequence they decided to suppress the pink ward because stealth based characters were struggling.
To compensate they decided to rework/ create a new invisibility stealth mechanic which totally destroyed balance in the game, some balanced characters became op and others became less impacting.
the oracle lens completely destroyed the utility of teemo's ult in late game.
Now you are destroying its ambush mecanic ? we can't longer wait under a shroom that someone walks into it ?
One of The basic teemo mecanics was to mine the field and wait with passive that somone walked in and kill him after.
AMBUSHING is a game mechanic that you seem to want to remove... Moreover you removed the best and fair counter The PINK ward...