I have been living and working in Jakarta / Tangerang since 2010 and have never seen a paper cheque or traveler's cheque in Indonesia. Where are all these people writing cheques?
Your time reference is since 2010 to this date?? Even today you could still exchange a traveller cheque for cash it in many money changers or big banks such as BCA, Bank BNI, but the rate is typically lower than bank notes also because of less convenience. But some people can not get credit card, debit card. Also because they still believe that Traveller cheque has an added security of needing an ID to be cashed.
Here for instance you could cash it in Bank BNI
www.bni.co.id
In Bali big money changers such as centralkuta, bmc, balibestrate will accept it but worse exchange rate than bank notes.
About paper cheque issued by the Indonesian banks to be used in Indonesia is much more prevalent especially if involving large sum of money. This is example of paper Cheque (e.g Bilyet Giro BG)", a paper cheque that could only be transferred to a bank account, not for cash.
The most famous case is "Akidi Tio" (Search it) want to write a BG for IDR2T in 2021. It is typically used to pay, to transfer money to someone else in large quantity. As usual in Indonesia, for small quantity cash is king or sometimes payment/fintech apps, for moderate sum Credit/debit cards. But you can not use this payment method involving a few hundred milions IDR.
Jagad media sosial dihebohkan dengan beredarnya foto bilyet giro Rp 2 triliun.
www.cnbcindonesia.com
Here are examples within your time frame (e.g after 2010).
Many people in Indonesia have been living in their cities / Villages for their whole life but they never see Jakarta, Bali, Surabaya as they do not even travel. Does it mean Jakarta, Bali, Surabaya do not exist ?? Many people do not need to transfer/pay a few hundred millions rupiahs so will not see the BG like the above. Does it mean BGs are not in use ??
Developed country with much more advanced financial system are still using paper cheques., paper instruments. In Europe for instance, Many building society, banks are still issuing paper cheque, you could exchange traveller cheque in any UK post offices. You could still convert your paper share certificate proving a shareholder's ownership in a company to electronic shares for a fee. But certainly the trend is in decline and gradually phased out as the emerging of
"open banking" as the future of payment/banking system is gradually developed.